Merging main

.github/actions/spell-check/allow/code.txt

@@ -335,3 +335,7 @@ azp
 feedbackhub
 needinfo
 reportbug
+
+#ffmpeg
+crf
+nostdin

.github/actions/spell-check/expect.txt

@@ -141,8 +141,11 @@ BITSPIXEL
 bla
 BLACKFRAME
 BLENDFUNCTION
+blittable
 Blockquotes
 blt
+bluelightreduction
+bluelightreductionstate
 BLURBEHIND
 BLURREGION
 bmi
@@ -250,6 +253,7 @@ colorformat
 colorhistory
 colorhistorylimit
 COLORKEY
+colorref
 comctl
 comdlg
 comexp
@@ -1113,6 +1117,7 @@ NEWPLUSSHELLEXTENSIONWIN
 newrow
 nicksnettravels
 NIF
+nightlight
 NLog
 NLSTEXT
 NMAKE
@@ -1483,6 +1488,7 @@ rgh
 rgn
 rgs
 rguid
+rhk
 RIDEV
 RIGHTSCROLLBAR
 riid
@@ -1588,6 +1594,7 @@ SHGDNF
 SHGFI
 SHIL
 shinfo
+shk
 shlwapi
 shobjidl
 SHORTCUTATLEAST
@@ -1858,8 +1865,10 @@ Uniquifies
 unitconverter
 unittests
 UNLEN
+Uninitializes
 UNORM
 unremapped
+Unsubscribes
 unvirtualized
 unwide
 unzoom

.pipelines/ESRPSigning_core.json

@@ -60,6 +60,8 @@
             "PowerToys.FancyZonesEditorCommon.dll",
             "PowerToys.FancyZonesModuleInterface.dll",
             "PowerToys.FancyZones.exe",
+            "FancyZonesCLI.exe",
+            "FancyZonesCLI.dll",
 
             "PowerToys.GcodePreviewHandler.dll",
             "PowerToys.GcodePreviewHandler.exe",
@@ -351,6 +353,11 @@
                 "Microsoft.SemanticKernel.Connectors.Ollama.dll",
                 "OllamaSharp.dll",
 
+                "boost_regex-vc143-mt-gd-x32-1_87.dll",
+                "boost_regex-vc143-mt-gd-x64-1_87.dll",
+                "boost_regex-vc143-mt-x32-1_87.dll",
+                "boost_regex-vc143-mt-x64-1_87.dll",
+
                 "UnitsNet.dll",
                 "UtfUnknown.dll",
                 "Wpf.Ui.dll"

.pipelines/versionAndSignCheck.ps1

@@ -52,7 +52,12 @@ $nullVersionExceptions = @(
     "System.Diagnostics.EventLog.Messages.dll",
     "Microsoft.Windows.Widgets.dll",
     "AdaptiveCards.ObjectModel.WinUI3.dll",
-    "AdaptiveCards.Rendering.WinUI3.dll") -join '|';
+    "AdaptiveCards.Rendering.WinUI3.dll",
+    "boost_regex_vc143_mt_gd_x32_1_87.dll",
+    "boost_regex_vc143_mt_gd_x64_1_87.dll",
+    "boost_regex_vc143_mt_x32_1_87.dll",
+    "boost_regex_vc143_mt_x64_1_87.dll"
+    ) -join '|';
 $totalFailure = 0;
 
 Write-Host $DirPath;

COMMUNITY.md

@@ -121,6 +121,9 @@ PowerToys Awake is a tool to keep your computer awake.
 
 Randy contributed Registry Preview and some very early conversations about keyboard remapping.
 
+### [@cinnamon-msft](https://github.com/cinnamon-msft) - Kayla Cinnamon
+Kayla was a former lead for PowerToys and helped create multiple utilities, maintained the GitHub repo, and collaborated with the community to improve the overall product
+
 ### [@oldnewthing](https://github.com/oldnewthing) - Raymond Chen
 
 Find My Mouse is based on Raymond Chen's SuperSonar.
@@ -180,7 +183,6 @@ ZoomIt source code was originally implemented by [Sysinternals](https://sysinter
 
 ## PowerToys core team
 
-- [@cinnamon-msft](https://github.com/cinnamon-msft) - Kayla Cinnamon - Lead
 - [@craigloewen-msft](https://github.com/craigloewen-msft) - Craig Loewen - Product Manager
 - [@niels9001](https://github.com/niels9001/) - Niels Laute - Product Manager
 - [@dhowett](https://github.com/dhowett) - Dustin Howett - Dev Lead
@@ -209,6 +211,7 @@ ZoomIt source code was originally implemented by [Sysinternals](https://sysinter
 ## Former PowerToys core team members
 
 - [@indierawk2k2](https://github.com/indierawk2k2) - Mike Harsh - Product Manager
+- [@cinnamon-msft](https://github.com/cinnamon-msft) - Kayla Cinnamon - Product Manager
 - [@ethanfangg](https://github.com/ethanfangg) - Ethan Fang - Product Manager
 - [@plante-msft](https://github.com/plante-msft) - Connor Plante - Product Manager
 - [@joadoumie](https://github.com/joadoumie) - Jordi Adoumie - Product Manager

Directory.Packages.props

@@ -40,6 +40,7 @@
     <PackageVersion Include="Microsoft.Data.Sqlite" Version="9.0.10" />
     <!-- Including Microsoft.Bcl.AsyncInterfaces to force version, since it's used by Microsoft.SemanticKernel. -->
     <PackageVersion Include="Microsoft.Bcl.AsyncInterfaces" Version="9.0.10" />
+    <PackageVersion Include="Microsoft.Graphics.Win2D" Version="1.3.2" />
     <PackageVersion Include="Microsoft.Windows.CppWinRT" Version="2.0.240111.5" />
     <PackageVersion Include="Microsoft.Diagnostics.Tracing.TraceEvent" Version="3.1.16" />
     <PackageVersion Include="Microsoft.Extensions.AI" Version="9.9.1" />

PowerToys.slnx

@@ -370,6 +370,10 @@
       <Platform Solution="*|x64" Project="x64" />
     </Project>
     <Project Path="src/modules/fancyzones/FancyZones/FancyZones.vcxproj" Id="ff1d7936-842a-4bbb-8bea-e9fe796de700" />
+    <Project Path="src/modules/fancyzones/FancyZonesCLI/FancyZonesCLI.csproj">
+      <Platform Solution="*|ARM64" Project="ARM64" />
+      <Platform Solution="*|x64" Project="x64" />
+    </Project>
     <Project Path="src/modules/fancyzones/FancyZonesEditorCommon/FancyZonesEditorCommon.csproj">
       <Platform Solution="*|ARM64" Project="ARM64" />
       <Platform Solution="*|x64" Project="x64" />

src/common/ManagedCsWin32/CLSID.cs

@@ -16,4 +16,5 @@ public static partial class CLSID
     public static readonly Guid CollatorDataSource = new Guid("9E175B8B-F52A-11D8-B9A5-505054503030");
     public static readonly Guid ApplicationActivationManager = new Guid("45BA127D-10A8-46EA-8AB7-56EA9078943C");
     public static readonly Guid VirtualDesktopManager = new("aa509086-5ca9-4c25-8f95-589d3c07b48a");
+    public static readonly Guid DesktopWallpaper = new("C2CF3110-460E-4FC1-B9D0-8A1C0C9CC4BD");
 }

src/common/ManagedCsWin32/Ole32.cs

@@ -16,6 +16,12 @@ public static partial class Ole32
         CLSCTX dwClsContext,
         ref Guid riid,
         out IntPtr rReturnedComObject);
+
+    [LibraryImport("ole32.dll")]
+    internal static partial int CoInitializeEx(nint pvReserved, uint dwCoInit);
+
+    [LibraryImport("ole32.dll")]
+    internal static partial void CoUninitialize();
 }
 
 [Flags]

src/common/UITestAutomation/ScreenRecording.cs

@@ -0,0 +1,399 @@
+// Copyright (c) Microsoft Corporation
+// The Microsoft Corporation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System;
+using System.Collections.Generic;
+using System.Diagnostics;
+using System.Drawing;
+using System.Drawing.Imaging;
+using System.IO;
+using System.Runtime.InteropServices;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace Microsoft.PowerToys.UITest
+{
+    /// <summary>
+    /// Provides methods for recording the screen during UI tests.
+    /// Requires FFmpeg to be installed and available in PATH.
+    /// </summary>
+    internal class ScreenRecording : IDisposable
+    {
+        private readonly string outputDirectory;
+        private readonly string framesDirectory;
+        private readonly string outputFilePath;
+        private readonly List<string> capturedFrames;
+        private readonly SemaphoreSlim recordingLock = new(1, 1);
+        private readonly Stopwatch recordingStopwatch = new();
+        private readonly string? ffmpegPath;
+        private CancellationTokenSource? recordingCancellation;
+        private Task? recordingTask;
+        private bool isRecording;
+        private int frameCount;
+
+        [DllImport("user32.dll")]
+        private static extern IntPtr GetDC(IntPtr hWnd);
+
+        [DllImport("gdi32.dll")]
+        private static extern int GetDeviceCaps(IntPtr hdc, int nIndex);
+
+        [DllImport("user32.dll")]
+        private static extern IntPtr ReleaseDC(IntPtr hWnd, IntPtr hDC);
+
+        [DllImport("user32.dll")]
+        private static extern bool GetCursorInfo(out ScreenCapture.CURSORINFO pci);
+
+        [DllImport("user32.dll")]
+        private static extern bool DrawIconEx(IntPtr hdc, int x, int y, IntPtr hIcon, int cx, int cy, int istepIfAniCur, IntPtr hbrFlickerFreeDraw, int diFlags);
+
+        private const int CURSORSHOWING = 0x00000001;
+        private const int DESKTOPHORZRES = 118;
+        private const int DESKTOPVERTRES = 117;
+        private const int DINORMAL = 0x0003;
+        private const int TargetFps = 15; // 15 FPS for good balance of quality and size
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="ScreenRecording"/> class.
+        /// </summary>
+        /// <param name="outputDirectory">Directory where the recording will be saved.</param>
+        public ScreenRecording(string outputDirectory)
+        {
+            this.outputDirectory = outputDirectory;
+            string timestamp = DateTime.Now.ToString("yyyyMMdd_HHmmss");
+            framesDirectory = Path.Combine(outputDirectory, $"frames_{timestamp}");
+            outputFilePath = Path.Combine(outputDirectory, $"recording_{timestamp}.mp4");
+            capturedFrames = new List<string>();
+            frameCount = 0;
+
+            // Check if FFmpeg is available
+            ffmpegPath = FindFfmpeg();
+            if (ffmpegPath == null)
+            {
+                Console.WriteLine("FFmpeg not found. Screen recording will be disabled.");
+                Console.WriteLine("To enable video recording, install FFmpeg: https://ffmpeg.org/download.html");
+            }
+        }
+
+        /// <summary>
+        /// Gets a value indicating whether screen recording is available (FFmpeg found).
+        /// </summary>
+        public bool IsAvailable => ffmpegPath != null;
+
+        /// <summary>
+        /// Starts recording the screen.
+        /// </summary>
+        /// <returns>A task representing the asynchronous operation.</returns>
+        public async Task StartRecordingAsync()
+        {
+            await recordingLock.WaitAsync();
+            try
+            {
+                if (isRecording || !IsAvailable)
+                {
+                    return;
+                }
+
+                // Create frames directory
+                Directory.CreateDirectory(framesDirectory);
+
+                recordingCancellation = new CancellationTokenSource();
+                isRecording = true;
+                recordingStopwatch.Start();
+
+                // Start the recording task
+                recordingTask = Task.Run(() => RecordFrames(recordingCancellation.Token));
+
+                Console.WriteLine($"Started screen recording at {TargetFps} FPS");
+            }
+            catch (Exception ex)
+            {
+                Console.WriteLine($"Failed to start recording: {ex.Message}");
+                isRecording = false;
+            }
+            finally
+            {
+                recordingLock.Release();
+            }
+        }
+
+        /// <summary>
+        /// Stops recording and encodes video.
+        /// </summary>
+        /// <returns>A task representing the asynchronous operation.</returns>
+        public async Task StopRecordingAsync()
+        {
+            await recordingLock.WaitAsync();
+            try
+            {
+                if (!isRecording || recordingCancellation == null)
+                {
+                    return;
+                }
+
+                // Signal cancellation
+                recordingCancellation.Cancel();
+
+                // Wait for recording task to complete
+                if (recordingTask != null)
+                {
+                    await recordingTask;
+                }
+
+                recordingStopwatch.Stop();
+                isRecording = false;
+
+                double duration = recordingStopwatch.Elapsed.TotalSeconds;
+                Console.WriteLine($"Recording stopped. Captured {capturedFrames.Count} frames in {duration:F2} seconds");
+
+                // Encode to video
+                await EncodeToVideoAsync();
+            }
+            catch (Exception ex)
+            {
+                Console.WriteLine($"Error stopping recording: {ex.Message}");
+            }
+            finally
+            {
+                Cleanup();
+                recordingLock.Release();
+            }
+        }
+
+        /// <summary>
+        /// Records frames from the screen.
+        /// </summary>
+        private void RecordFrames(CancellationToken cancellationToken)
+        {
+            try
+            {
+                int frameInterval = 1000 / TargetFps;
+                var frameTimer = Stopwatch.StartNew();
+
+                while (!cancellationToken.IsCancellationRequested)
+                {
+                    var frameStart = frameTimer.ElapsedMilliseconds;
+
+                    try
+                    {
+                        CaptureFrame();
+                    }
+                    catch (Exception ex)
+                    {
+                        Console.WriteLine($"Error capturing frame: {ex.Message}");
+                    }
+
+                    // Sleep for remaining time to maintain target FPS
+                    var frameTime = frameTimer.ElapsedMilliseconds - frameStart;
+                    var sleepTime = Math.Max(0, frameInterval - (int)frameTime);
+
+                    if (sleepTime > 0)
+                    {
+                        Thread.Sleep(sleepTime);
+                    }
+                }
+            }
+            catch (OperationCanceledException)
+            {
+                // Expected when stopping
+            }
+            catch (Exception ex)
+            {
+                Console.WriteLine($"Error during recording: {ex.Message}");
+            }
+        }
+
+        /// <summary>
+        /// Captures a single frame.
+        /// </summary>
+        private void CaptureFrame()
+        {
+            IntPtr hdc = GetDC(IntPtr.Zero);
+            int screenWidth = GetDeviceCaps(hdc, DESKTOPHORZRES);
+            int screenHeight = GetDeviceCaps(hdc, DESKTOPVERTRES);
+            ReleaseDC(IntPtr.Zero, hdc);
+
+            Rectangle bounds = new Rectangle(0, 0, screenWidth, screenHeight);
+            using (Bitmap bitmap = new Bitmap(bounds.Width, bounds.Height, PixelFormat.Format24bppRgb))
+            {
+                using (Graphics g = Graphics.FromImage(bitmap))
+                {
+                    g.CopyFromScreen(bounds.Location, Point.Empty, bounds.Size);
+
+                    ScreenCapture.CURSORINFO cursorInfo;
+                    cursorInfo.CbSize = Marshal.SizeOf<ScreenCapture.CURSORINFO>();
+                    if (GetCursorInfo(out cursorInfo) && cursorInfo.Flags == CURSORSHOWING)
+                    {
+                        IntPtr hdcDest = g.GetHdc();
+                        DrawIconEx(hdcDest, cursorInfo.PTScreenPos.X, cursorInfo.PTScreenPos.Y, cursorInfo.HCursor, 0, 0, 0, IntPtr.Zero, DINORMAL);
+                        g.ReleaseHdc(hdcDest);
+                    }
+                }
+
+                string framePath = Path.Combine(framesDirectory, $"frame_{frameCount:D6}.jpg");
+                bitmap.Save(framePath, ImageFormat.Jpeg);
+                capturedFrames.Add(framePath);
+                frameCount++;
+            }
+        }
+
+        /// <summary>
+        /// Encodes captured frames to video using ffmpeg.
+        /// </summary>
+        private async Task EncodeToVideoAsync()
+        {
+            if (capturedFrames.Count == 0)
+            {
+                Console.WriteLine("No frames captured");
+                return;
+            }
+
+            try
+            {
+                // Build ffmpeg command with proper non-interactive flags
+                string inputPattern = Path.Combine(framesDirectory, "frame_%06d.jpg");
+
+                // -y: overwrite without asking
+                // -nostdin: disable interaction
+                // -loglevel error: only show errors
+                // -stats: show encoding progress
+                string args = $"-y -nostdin -loglevel error -stats -framerate {TargetFps} -i \"{inputPattern}\" -c:v libx264 -pix_fmt yuv420p -crf 23 \"{outputFilePath}\"";
+
+                Console.WriteLine($"Encoding {capturedFrames.Count} frames to video...");
+
+                var startInfo = new ProcessStartInfo
+                {
+                    FileName = ffmpegPath!,
+                    Arguments = args,
+                    UseShellExecute = false,
+                    RedirectStandardOutput = true,
+                    RedirectStandardError = true,
+                    RedirectStandardInput = true, // Important: redirect stdin to prevent hanging
+                    CreateNoWindow = true,
+                };
+
+                using var process = Process.Start(startInfo);
+                if (process != null)
+                {
+                    // Close stdin immediately to ensure FFmpeg doesn't wait for input
+                    process.StandardInput.Close();
+
+                    // Read output streams asynchronously to prevent deadlock
+                    var outputTask = process.StandardOutput.ReadToEndAsync();
+                    var errorTask = process.StandardError.ReadToEndAsync();
+
+                    // Wait for process to exit
+                    await process.WaitForExitAsync();
+
+                    // Get the output
+                    string stdout = await outputTask;
+                    string stderr = await errorTask;
+
+                    if (process.ExitCode == 0 && File.Exists(outputFilePath))
+                    {
+                        var fileInfo = new FileInfo(outputFilePath);
+                        Console.WriteLine($"Video created: {outputFilePath} ({fileInfo.Length / 1024 / 1024:F1} MB)");
+                    }
+                    else
+                    {
+                        Console.WriteLine($"FFmpeg encoding failed with exit code {process.ExitCode}");
+                        if (!string.IsNullOrWhiteSpace(stderr))
+                        {
+                            Console.WriteLine($"FFmpeg error: {stderr}");
+                        }
+                    }
+                }
+            }
+            catch (Exception ex)
+            {
+                Console.WriteLine($"Error encoding video: {ex.Message}");
+            }
+        }
+
+        /// <summary>
+        /// Finds ffmpeg executable.
+        /// </summary>
+        private static string? FindFfmpeg()
+        {
+            // Check if ffmpeg is in PATH
+            var pathDirs = Environment.GetEnvironmentVariable("PATH")?.Split(Path.PathSeparator) ?? Array.Empty<string>();
+
+            foreach (var dir in pathDirs)
+            {
+                var ffmpegPath = Path.Combine(dir, "ffmpeg.exe");
+                if (File.Exists(ffmpegPath))
+                {
+                    return ffmpegPath;
+                }
+            }
+
+            // Check common installation locations
+            var commonPaths = new[]
+            {
+                @"C:\.tools\ffmpeg\bin\ffmpeg.exe",
+                @"C:\ffmpeg\bin\ffmpeg.exe",
+                @"C:\Program Files\ffmpeg\bin\ffmpeg.exe",
+                @"C:\Program Files (x86)\ffmpeg\bin\ffmpeg.exe",
+                @$"{Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData)}\Microsoft\WinGet\Links\ffmpeg.exe",
+            };
+
+            foreach (var path in commonPaths)
+            {
+                if (File.Exists(path))
+                {
+                    return path;
+                }
+            }
+
+            return null;
+        }
+
+        /// <summary>
+        /// Gets the path to the recorded video file.
+        /// </summary>
+        public string OutputFilePath => outputFilePath;
+
+        /// <summary>
+        /// Gets the directory containing recordings.
+        /// </summary>
+        public string OutputDirectory => outputDirectory;
+
+        /// <summary>
+        /// Cleans up resources.
+        /// </summary>
+        private void Cleanup()
+        {
+            recordingCancellation?.Dispose();
+            recordingCancellation = null;
+            recordingTask = null;
+
+            // Clean up frames directory if it exists
+            try
+            {
+                if (Directory.Exists(framesDirectory))
+                {
+                    Directory.Delete(framesDirectory, true);
+                }
+            }
+            catch (Exception ex)
+            {
+                Console.WriteLine($"Failed to cleanup frames directory: {ex.Message}");
+            }
+        }
+
+        /// <summary>
+        /// Disposes resources.
+        /// </summary>
+        public void Dispose()
+        {
+            if (isRecording)
+            {
+                StopRecordingAsync().GetAwaiter().GetResult();
+            }
+
+            Cleanup();
+            recordingLock.Dispose();
+            GC.SuppressFinalize(this);
+        }
+    }
+}

src/common/UITestAutomation/SessionHelper.cs

@@ -130,9 +130,13 @@ namespace Microsoft.PowerToys.UITest
         /// </summary>
         /// <param name="appPath">The path to the application executable.</param>
         /// <param name="args">Optional command line arguments to pass to the application.</param>
-        public void StartExe(string appPath, string[]? args = null)
+        public void StartExe(string appPath, string[]? args = null, string? enableModules = null)
         {
             var opts = new AppiumOptions();
+            if (!string.IsNullOrEmpty(enableModules))
+            {
+                opts.AddAdditionalCapability("enableModules", enableModules);
+            }
 
             if (scope == PowerToysModule.PowerToysSettings)
             {
@@ -169,27 +173,66 @@ namespace Microsoft.PowerToys.UITest
 
         private void TryLaunchPowerToysSettings(AppiumOptions opts)
         {
-            try
+            if (opts.ToCapabilities().HasCapability("enableModules"))
             {
-                var runnerProcessInfo = new ProcessStartInfo
+                var modulesString = (string)opts.ToCapabilities().GetCapability("enableModules");
+                var modulesArray = modulesString.Split(',', StringSplitOptions.RemoveEmptyEntries | StringSplitOptions.TrimEntries);
+                SettingsConfigHelper.ConfigureGlobalModuleSettings(modulesArray);
+            }
+            else
+            {
+                SettingsConfigHelper.ConfigureGlobalModuleSettings();
+            }
+
+            const int maxTries = 3;
+            const int delayMs = 5000;
+            const int maxRetries = 3;
+
+            for (int tryCount = 1; tryCount <= maxTries; tryCount++)
+            {
+                try
                 {
-                    FileName = locationPath + runnerPath,
-                    Verb = "runas",
-                    Arguments = "--open-settings",
-                };
+                    var runnerProcessInfo = new ProcessStartInfo
+                    {
+                        FileName = locationPath + runnerPath,
+                        Verb = "runas",
+                        Arguments = "--open-settings",
+                    };
 
-                ExitExe(runnerProcessInfo.FileName);
-                runner = Process.Start(runnerProcessInfo);
+                    ExitExe(runnerProcessInfo.FileName);
 
-                WaitForWindowAndSetCapability(opts, "PowerToys Settings", 5000, 5);
+                    // Verify process was killed
+                    string exeName = Path.GetFileNameWithoutExtension(runnerProcessInfo.FileName);
+                    var remainingProcesses = Process.GetProcessesByName(exeName);
 
-                // Exit CmdPal UI before launching new process if use installer for test
-                ExitExeByName("Microsoft.CmdPal.UI");
-            }
-            catch (Exception ex)
-            {
-                throw new InvalidOperationException($"Failed to launch PowerToys Settings: {ex.Message}", ex);
+                    runner = Process.Start(runnerProcessInfo);
+
+                    if (WaitForWindowAndSetCapability(opts, "PowerToys Settings", delayMs, maxRetries))
+                    {
+                        // Exit CmdPal UI before launching new process if use installer for test
+                        ExitExeByName("Microsoft.CmdPal.UI");
+                        return;
+                    }
+
+                    // Window not found, kill all PowerToys processes and retry
+                    if (tryCount < maxTries)
+                    {
+                        KillPowerToysProcesses();
+                    }
+                }
+                catch (Exception ex)
+                {
+                    if (tryCount == maxTries)
+                    {
+                        throw new InvalidOperationException($"Failed to launch PowerToys Settings after {maxTries} attempts: {ex.Message}", ex);
+                    }
+
+                    // Kill processes and retry
+                    KillPowerToysProcesses();
+                }
             }
+
+            throw new InvalidOperationException($"Failed to launch PowerToys Settings: Window not found after {maxTries} attempts.");
         }
 
         private void TryLaunchCommandPalette(AppiumOptions opts)
@@ -211,7 +254,10 @@ namespace Microsoft.PowerToys.UITest
                 var process = Process.Start(processStartInfo);
                 process?.WaitForExit();
 
-                WaitForWindowAndSetCapability(opts, "Command Palette", 5000, 10);
+                if (!WaitForWindowAndSetCapability(opts, "Command Palette", 5000, 10))
+                {
+                    throw new TimeoutException("Failed to find Command Palette window after multiple attempts.");
+                }
             }
             catch (Exception ex)
             {
@@ -219,7 +265,7 @@ namespace Microsoft.PowerToys.UITest
             }
         }
 
-        private void WaitForWindowAndSetCapability(AppiumOptions opts, string windowName, int delayMs, int maxRetries)
+        private bool WaitForWindowAndSetCapability(AppiumOptions opts, string windowName, int delayMs, int maxRetries)
         {
             for (int attempt = 1; attempt <= maxRetries; attempt++)
             {
@@ -230,18 +276,16 @@ namespace Microsoft.PowerToys.UITest
                 {
                     var hexHwnd = window[0].HWnd.ToString("x");
                     opts.AddAdditionalCapability("appTopLevelWindow", hexHwnd);
-                    return;
+                    return true;
                 }
 
                 if (attempt < maxRetries)
                 {
                     Thread.Sleep(delayMs);
                 }
-                else
-                {
-                    throw new TimeoutException($"Failed to find {windowName} window after multiple attempts.");
-                }
             }
+
+            return false;
         }
 
         /// <summary>
@@ -292,17 +336,17 @@ namespace Microsoft.PowerToys.UITest
             catch (Exception ex)
             {
                 // Handle exceptions if needed
-                Debug.WriteLine($"Exception during Cleanup: {ex.Message}");
+                Console.WriteLine($"Exception during Cleanup: {ex.Message}");
             }
         }
 
         /// <summary>
         /// Restarts now exe and takes control of it.
         /// </summary>
-        public void RestartScopeExe()
+        public void RestartScopeExe(string? enableModules = null)
         {
             ExitScopeExe();
-            StartExe(locationPath + sessionPath, this.commandLineArgs);
+            StartExe(locationPath + sessionPath, commandLineArgs, enableModules);
         }
 
         public WindowsDriver<WindowsElement> GetRoot()
@@ -327,5 +371,31 @@ namespace Microsoft.PowerToys.UITest
             this.ExitExe(winAppDriverProcessInfo.FileName);
             SessionHelper.appDriver = Process.Start(winAppDriverProcessInfo);
         }
+
+        private void KillPowerToysProcesses()
+        {
+            var powerToysProcessNames = new[] { "PowerToys", "Microsoft.CmdPal.UI" };
+
+            foreach (var processName in powerToysProcessNames)
+            {
+                try
+                {
+                    var processes = Process.GetProcessesByName(processName);
+
+                    foreach (var process in processes)
+                    {
+                        process.Kill();
+                        process.WaitForExit();
+                    }
+
+                    // Verify processes are actually gone
+                    var remainingProcesses = Process.GetProcessesByName(processName);
+                }
+                catch (Exception ex)
+                {
+                    Console.WriteLine($"[KillPowerToysProcesses] Failed to kill process {processName}: {ex.Message}");
+                }
+            }
+        }
     }
 }

src/common/UITestAutomation/SettingsConfigHelper.cs

@@ -26,14 +26,13 @@ namespace Microsoft.PowerToys.UITest
         /// <summary>
         /// Configures global PowerToys settings to enable only specified modules and disable all others.
         /// </summary>
-        /// <param name="modulesToEnable">Array of module names to enable (e.g., "Peek", "FancyZones"). All other modules will be disabled.</param>
-        /// <exception cref="ArgumentNullException">Thrown when modulesToEnable is null.</exception>
+        /// <param name="modulesToEnable">Array of module names to enable (e.g., "Peek", "FancyZones"). All other modules will be disabled. If null or empty, all modules will be disabled.</param>
         /// <exception cref="InvalidOperationException">Thrown when settings file operations fail.</exception>
         [UnconditionalSuppressMessage("Trimming", "IL2026", Justification = "This is test code and will not be trimmed")]
         [UnconditionalSuppressMessage("AOT", "IL3050", Justification = "This is test code and will not be AOT compiled")]
-        public static void ConfigureGlobalModuleSettings(params string[] modulesToEnable)
+        public static void ConfigureGlobalModuleSettings(params string[]? modulesToEnable)
         {
-            ArgumentNullException.ThrowIfNull(modulesToEnable);
+            modulesToEnable ??= Array.Empty<string>();
 
             try
             {

src/common/UITestAutomation/UITestBase.cs

@@ -29,6 +29,8 @@ namespace Microsoft.PowerToys.UITest
 
         public string? ScreenshotDirectory { get; set; }
 
+        public string? RecordingDirectory { get; set; }
+
         public static MonitorInfoData.ParamsWrapper MonitorInfoData { get; set; } = new MonitorInfoData.ParamsWrapper() { Monitors = new List<MonitorInfoData.MonitorInfoDataWrapper>() };
 
         private readonly PowerToysModule scope;
@@ -36,6 +38,7 @@ namespace Microsoft.PowerToys.UITest
         private readonly string[]? commandLineArgs;
         private SessionHelper? sessionHelper;
         private System.Threading.Timer? screenshotTimer;
+        private ScreenRecording? screenRecording;
 
         public UITestBase(PowerToysModule scope = PowerToysModule.PowerToysSettings, WindowSize size = WindowSize.UnSpecified, string[]? commandLineArgs = null)
         {
@@ -65,12 +68,35 @@ namespace Microsoft.PowerToys.UITest
             CloseOtherApplications();
             if (IsInPipeline)
             {
-                ScreenshotDirectory = Path.Combine(this.TestContext.TestResultsDirectory ?? string.Empty, "UITestScreenshots_" + Guid.NewGuid().ToString());
+                string baseDirectory = this.TestContext.TestResultsDirectory ?? string.Empty;
+                ScreenshotDirectory = Path.Combine(baseDirectory, "UITestScreenshots_" + Guid.NewGuid().ToString());
                 Directory.CreateDirectory(ScreenshotDirectory);
 
+                RecordingDirectory = Path.Combine(baseDirectory, "UITestRecordings_" + Guid.NewGuid().ToString());
+                Directory.CreateDirectory(RecordingDirectory);
+
                 // Take screenshot every 1 second
                 screenshotTimer = new System.Threading.Timer(ScreenCapture.TimerCallback, ScreenshotDirectory, TimeSpan.Zero, TimeSpan.FromMilliseconds(1000));
 
+                // Start screen recording (requires FFmpeg)
+                try
+                {
+                    screenRecording = new ScreenRecording(RecordingDirectory);
+                    if (screenRecording.IsAvailable)
+                    {
+                        _ = screenRecording.StartRecordingAsync();
+                    }
+                    else
+                    {
+                        screenRecording = null;
+                    }
+                }
+                catch (Exception ex)
+                {
+                    Console.WriteLine($"Failed to start screen recording: {ex.Message}");
+                    screenRecording = null;
+                }
+
                 // Escape Popups before starting
                 System.Windows.Forms.SendKeys.SendWait("{ESC}");
             }
@@ -88,15 +114,36 @@ namespace Microsoft.PowerToys.UITest
             if (IsInPipeline)
             {
                 screenshotTimer?.Change(Timeout.Infinite, Timeout.Infinite);
-                Dispose();
+
+                // Stop screen recording
+                if (screenRecording != null)
+                {
+                    try
+                    {
+                        screenRecording.StopRecordingAsync().GetAwaiter().GetResult();
+                    }
+                    catch (Exception ex)
+                    {
+                        Console.WriteLine($"Failed to stop screen recording: {ex.Message}");
+                    }
+                }
+
                 if (TestContext.CurrentTestOutcome is UnitTestOutcome.Failed
                     or UnitTestOutcome.Error
                     or UnitTestOutcome.Unknown)
                 {
                     Task.Delay(1000).Wait();
                     AddScreenShotsToTestResultsDirectory();
+                    AddRecordingsToTestResultsDirectory();
                     AddLogFilesToTestResultsDirectory();
                 }
+                else
+                {
+                    // Clean up recording if test passed
+                    CleanupRecordingDirectory();
+                }
+
+                Dispose();
             }
 
             this.Session.Cleanup();
@@ -106,6 +153,7 @@ namespace Microsoft.PowerToys.UITest
         public void Dispose()
         {
             screenshotTimer?.Dispose();
+            screenRecording?.Dispose();
             GC.SuppressFinalize(this);
         }
 
@@ -600,6 +648,47 @@ namespace Microsoft.PowerToys.UITest
             }
         }
 
+        /// <summary>
+        /// Adds screen recordings to test results directory when test fails.
+        /// </summary>
+        protected void AddRecordingsToTestResultsDirectory()
+        {
+            if (RecordingDirectory != null && Directory.Exists(RecordingDirectory))
+            {
+                // Add video files (MP4)
+                var videoFiles = Directory.GetFiles(RecordingDirectory, "*.mp4");
+                foreach (string file in videoFiles)
+                {
+                    this.TestContext.AddResultFile(file);
+                    var fileInfo = new FileInfo(file);
+                    Console.WriteLine($"Added video recording: {Path.GetFileName(file)} ({fileInfo.Length / 1024 / 1024:F1} MB)");
+                }
+
+                if (videoFiles.Length == 0)
+                {
+                    Console.WriteLine("No video recording available (FFmpeg not found). Screenshots are still captured.");
+                }
+            }
+        }
+
+        /// <summary>
+        /// Cleans up recording directory when test passes.
+        /// </summary>
+        private void CleanupRecordingDirectory()
+        {
+            if (RecordingDirectory != null && Directory.Exists(RecordingDirectory))
+            {
+                try
+                {
+                    Directory.Delete(RecordingDirectory, true);
+                }
+                catch (Exception ex)
+                {
+                    Console.WriteLine($"Failed to cleanup recording directory: {ex.Message}");
+                }
+            }
+        }
+
         /// <summary>
         /// Copies PowerToys log files to test results directory when test fails.
         /// Renames files to include the directory structure after \PowerToys.
@@ -689,11 +778,11 @@ namespace Microsoft.PowerToys.UITest
         /// <summary>
         /// Restart scope exe.
         /// </summary>
-        public void RestartScopeExe()
+        public Session RestartScopeExe(string? enableModules = null)
         {
-            this.sessionHelper!.RestartScopeExe();
+            this.sessionHelper!.RestartScopeExe(enableModules);
             this.Session = new Session(this.sessionHelper.GetRoot(), this.sessionHelper.GetDriver(), this.scope, this.size);
-            return;
+            return Session;
         }
 
         /// <summary>

src/modules/LightSwitch/LightSwitchModuleInterface/dllmain.cpp

@@ -50,6 +50,7 @@ enum class ScheduleMode
     Off,
     FixedHours,
     SunsetToSunrise,
+    FollowNightLight,
     // add more later
 };
 
@@ -61,6 +62,8 @@ inline std::wstring ToString(ScheduleMode mode)
         return L"SunsetToSunrise";
     case ScheduleMode::FixedHours:
         return L"FixedHours";
+    case ScheduleMode::FollowNightLight:
+        return L"FollowNightLight";
     default:
         return L"Off";
     }
@@ -72,6 +75,8 @@ inline ScheduleMode FromString(const std::wstring& str)
         return ScheduleMode::SunsetToSunrise;
     if (str == L"FixedHours")
         return ScheduleMode::FixedHours;
+    if (str == L"FollowNightLight")
+        return ScheduleMode::FollowNightLight;
     return ScheduleMode::Off;
 }
 
@@ -167,7 +172,9 @@ public:
             ToString(g_settings.m_scheduleMode),
             { { L"Off", L"Disable the schedule" },
               { L"FixedHours", L"Set hours manually" },
-              { L"SunsetToSunrise", L"Use sunrise/sunset times" } });
+              { L"SunsetToSunrise", L"Use sunrise/sunset times" },
+              { L"FollowNightLight", L"Follow Windows Night Light state" }
+            });
 
         // Integer spinners
         settings.add_int_spinner(

src/modules/LightSwitch/LightSwitchService/LightSwitchService.cpp

@@ -13,10 +13,12 @@
 #include <utils/logger_helper.h>
 #include "LightSwitchStateManager.h"
 #include <LightSwitchUtils.h>
+#include <NightLightRegistryObserver.h>
 
 SERVICE_STATUS g_ServiceStatus = {};
 SERVICE_STATUS_HANDLE g_StatusHandle = nullptr;
 HANDLE g_ServiceStopEvent = nullptr;
+static LightSwitchStateManager* g_stateManagerPtr = nullptr;
 
 VOID WINAPI ServiceMain(DWORD argc, LPTSTR* argv);
 VOID WINAPI ServiceCtrlHandler(DWORD dwCtrl);
@@ -168,7 +170,15 @@ static void DetectAndHandleExternalThemeChange(LightSwitchStateManager& stateMan
     }
 
     // Use shared helper (handles wraparound logic)
-    bool shouldBeLight = ShouldBeLight(nowMinutes, effectiveLight, effectiveDark);
+    bool shouldBeLight = false;
+    if (s.scheduleMode == ScheduleMode::FollowNightLight)
+    {
+        shouldBeLight = !IsNightLightEnabled();
+    } 
+    else
+    {
+        shouldBeLight = ShouldBeLight(nowMinutes, effectiveLight, effectiveDark);
+    }
 
     // Compare current system/apps theme
     bool currentSystemLight = GetCurrentSystemTheme();
@@ -199,15 +209,40 @@ DWORD WINAPI ServiceWorkerThread(LPVOID lpParam)
     // Initialization
     // ────────────────────────────────────────────────────────────────
     static LightSwitchStateManager stateManager;
+    g_stateManagerPtr = &stateManager;
 
     LightSwitchSettings::instance().InitFileWatcher();
 
     HANDLE hManualOverride = OpenEventW(SYNCHRONIZE | EVENT_MODIFY_STATE, FALSE, L"POWERTOYS_LIGHTSWITCH_MANUAL_OVERRIDE");
     HANDLE hSettingsChanged = LightSwitchSettings::instance().GetSettingsChangedEvent();
 
+    static std::unique_ptr<NightLightRegistryObserver> g_nightLightWatcher;
+
     LightSwitchSettings::instance().LoadSettings();
     const auto& settings = LightSwitchSettings::instance().settings();
 
+    // after loading settings:
+    bool nightLightNeeded = (settings.scheduleMode == ScheduleMode::FollowNightLight);
+
+    if (nightLightNeeded && !g_nightLightWatcher)
+    {
+        Logger::info(L"[LightSwitchService] Starting Night Light registry watcher...");
+
+        g_nightLightWatcher = std::make_unique<NightLightRegistryObserver>(
+            HKEY_CURRENT_USER,
+            NIGHT_LIGHT_REGISTRY_PATH,
+            []() {
+                if (g_stateManagerPtr)
+                    g_stateManagerPtr->OnNightLightChange();
+            });
+    }
+    else if (!nightLightNeeded && g_nightLightWatcher)
+    {
+        Logger::info(L"[LightSwitchService] Stopping Night Light registry watcher...");
+        g_nightLightWatcher->Stop();
+        g_nightLightWatcher.reset();
+    }
+
     SYSTEMTIME st;
     GetLocalTime(&st);
     int nowMinutes = st.wHour * 60 + st.wMinute;
@@ -274,6 +309,31 @@ DWORD WINAPI ServiceWorkerThread(LPVOID lpParam)
             ResetEvent(hSettingsChanged);
             LightSwitchSettings::instance().LoadSettings();
             stateManager.OnSettingsChanged();
+
+            const auto& settings = LightSwitchSettings::instance().settings();
+            bool nightLightNeeded = (settings.scheduleMode == ScheduleMode::FollowNightLight);
+
+            if (nightLightNeeded && !g_nightLightWatcher)
+            {
+                Logger::info(L"[LightSwitchService] Starting Night Light registry watcher...");
+
+                g_nightLightWatcher = std::make_unique<NightLightRegistryObserver>(
+                    HKEY_CURRENT_USER,
+                    NIGHT_LIGHT_REGISTRY_PATH,
+                    []() {
+                        if (g_stateManagerPtr)
+                            g_stateManagerPtr->OnNightLightChange();
+                    });
+
+                stateManager.OnNightLightChange();
+            }
+            else if (!nightLightNeeded && g_nightLightWatcher)
+            {
+                Logger::info(L"[LightSwitchService] Stopping Night Light registry watcher...");
+                g_nightLightWatcher->Stop();
+                g_nightLightWatcher.reset();
+            }
+
             continue;
         }
     }
@@ -285,6 +345,11 @@ DWORD WINAPI ServiceWorkerThread(LPVOID lpParam)
         CloseHandle(hManualOverride);
     if (hParent)
         CloseHandle(hParent);
+    if (g_nightLightWatcher)
+    {
+        g_nightLightWatcher->Stop();
+        g_nightLightWatcher.reset();
+    }
 
     Logger::info(L"[LightSwitchService] Worker thread exiting cleanly.");
     return 0;

src/modules/LightSwitch/LightSwitchService/LightSwitchService.vcxproj

@@ -76,6 +76,7 @@
     <ClCompile Include="LightSwitchService.cpp" />
     <ClCompile Include="LightSwitchSettings.cpp" />
     <ClCompile Include="LightSwitchStateManager.cpp" />
+    <ClCompile Include="NightLightRegistryObserver.cpp" />
     <ClCompile Include="SettingsConstants.cpp" />
     <ClCompile Include="ThemeHelper.cpp" />
     <ClCompile Include="ThemeScheduler.cpp" />
@@ -88,6 +89,7 @@
     <ClInclude Include="LightSwitchSettings.h" />
     <ClInclude Include="LightSwitchStateManager.h" />
     <ClInclude Include="LightSwitchUtils.h" />
+    <ClInclude Include="NightLightRegistryObserver.h" />
     <ClInclude Include="SettingsConstants.h" />
     <ClInclude Include="SettingsObserver.h" />
     <ClInclude Include="ThemeHelper.h" />

src/modules/LightSwitch/LightSwitchService/LightSwitchService.vcxproj.filters

@@ -36,6 +36,9 @@
     <ClCompile Include="LightSwitchStateManager.cpp">
       <Filter>Source Files</Filter>
     </ClCompile>
+    <ClCompile Include="NightLightRegistryObserver.cpp">
+      <Filter>Source Files</Filter>
+    </ClCompile>
   </ItemGroup>
   <ItemGroup>
     <ClInclude Include="ThemeScheduler.h">
@@ -62,6 +65,9 @@
     <ClInclude Include="LightSwitchUtils.h">
       <Filter>Header Files</Filter>
     </ClInclude>
+    <ClInclude Include="NightLightRegistryObserver.h">
+      <Filter>Header Files</Filter>
+    </ClInclude>
   </ItemGroup>
   <ItemGroup>
     <Natvis Include="$(MSBuildThisFileDirectory)..\..\natvis\wil.natvis" />

src/modules/LightSwitch/LightSwitchService/LightSwitchSettings.h

@@ -19,7 +19,8 @@ enum class ScheduleMode
 {
     Off,
     FixedHours,
-    SunsetToSunrise
+    SunsetToSunrise,
+    FollowNightLight,
     // Add more in the future
 };
 
@@ -31,6 +32,8 @@ inline std::wstring ToString(ScheduleMode mode)
         return L"FixedHours";
     case ScheduleMode::SunsetToSunrise:
         return L"SunsetToSunrise";
+    case ScheduleMode::FollowNightLight:
+        return L"FollowNightLight";
     default:
         return L"Off";
     }
@@ -42,6 +45,8 @@ inline ScheduleMode FromString(const std::wstring& str)
         return ScheduleMode::SunsetToSunrise;
     if (str == L"FixedHours")
         return ScheduleMode::FixedHours;
+    if (str == L"FollowNightLight")
+        return ScheduleMode::FollowNightLight;
     else
         return ScheduleMode::Off;
 }

src/modules/LightSwitch/LightSwitchService/LightSwitchStateManager.cpp

@@ -31,7 +31,10 @@ void LightSwitchStateManager::OnSettingsChanged()
 void LightSwitchStateManager::OnTick(int currentMinutes)
 {
     std::lock_guard<std::mutex> lock(_stateMutex);
-    EvaluateAndApplyIfNeeded();
+    if (_state.lastAppliedMode != ScheduleMode::FollowNightLight)
+    {
+        EvaluateAndApplyIfNeeded();
+    }
 }
 
 // Called when manual override is triggered
@@ -49,8 +52,38 @@ void LightSwitchStateManager::OnManualOverride()
         _state.isAppsLightActive = GetCurrentAppsTheme();
 
         Logger::debug(L"[LightSwitchStateManager] Synced internal theme state to current system theme ({}) and apps theme ({}).",
-                     (_state.isSystemLightActive ? L"light" : L"dark"),
-                     (_state.isAppsLightActive ? L"light" : L"dark"));
+                      (_state.isSystemLightActive ? L"light" : L"dark"),
+                      (_state.isAppsLightActive ? L"light" : L"dark"));
+    }
+
+    EvaluateAndApplyIfNeeded();
+}
+
+// Runs with the registry observer detects a change in Night Light settings.
+void LightSwitchStateManager::OnNightLightChange()
+{
+    std::lock_guard<std::mutex> lock(_stateMutex);
+
+    bool newNightLightState = IsNightLightEnabled();
+
+    // In Follow Night Light mode, treat a Night Light toggle as a boundary
+    if (_state.lastAppliedMode == ScheduleMode::FollowNightLight && _state.isManualOverride)
+    {
+        Logger::info(L"[LightSwitchStateManager] Night Light changed while manual override active; "
+                     L"treating as a boundary and clearing manual override.");
+        _state.isManualOverride = false;
+    }
+
+    if (newNightLightState != _state.isNightLightActive)
+    {
+        Logger::info(L"[LightSwitchStateManager] Night Light toggled to {}",
+                     newNightLightState ? L"ON" : L"OFF");
+
+        _state.isNightLightActive = newNightLightState;
+    }
+    else
+    {
+        Logger::debug(L"[LightSwitchStateManager] Night Light change event fired, but no actual change.");
     }
 
     EvaluateAndApplyIfNeeded();
@@ -77,9 +110,9 @@ void LightSwitchStateManager::SyncInitialThemeState()
     _state.isSystemLightActive = GetCurrentSystemTheme();
     _state.isAppsLightActive = GetCurrentAppsTheme();
     Logger::debug(L"[LightSwitchStateManager] Synced initial state to current system theme ({})",
-                 _state.isSystemLightActive ? L"light" : L"dark");
+                  _state.isSystemLightActive ? L"light" : L"dark");
     Logger::debug(L"[LightSwitchStateManager] Synced initial state to current apps theme ({})",
-                 _state.isAppsLightActive ? L"light" : L"dark");
+                  _state.isAppsLightActive ? L"light" : L"dark");
 }
 
 static std::pair<int, int> update_sun_times(auto& settings)
@@ -194,7 +227,15 @@ void LightSwitchStateManager::EvaluateAndApplyIfNeeded()
 
     _state.lastAppliedMode = _currentSettings.scheduleMode;
 
-    bool shouldBeLight = ShouldBeLight(now, _state.effectiveLightMinutes, _state.effectiveDarkMinutes);
+    bool shouldBeLight = false;
+    if (_currentSettings.scheduleMode == ScheduleMode::FollowNightLight)
+    {
+        shouldBeLight = !_state.isNightLightActive;
+    }
+    else
+    {
+        shouldBeLight = ShouldBeLight(now, _state.effectiveLightMinutes, _state.effectiveDarkMinutes);
+    }
 
     bool appsNeedsToChange = _currentSettings.changeApps && (_state.isAppsLightActive != shouldBeLight);
     bool systemNeedsToChange = _currentSettings.changeSystem && (_state.isSystemLightActive != shouldBeLight);
@@ -227,6 +268,3 @@ void LightSwitchStateManager::EvaluateAndApplyIfNeeded()
 
     _state.lastTickMinutes = now;
 }
-
-
-

src/modules/LightSwitch/LightSwitchService/LightSwitchStateManager.h

@@ -9,6 +9,7 @@ struct LightSwitchState
     bool isManualOverride = false;
     bool isSystemLightActive = false;
     bool isAppsLightActive = false;
+    bool isNightLightActive = false;
     int lastEvaluatedDay = -1;
     int lastTickMinutes = -1;
 
@@ -32,6 +33,9 @@ public:
     // Called when manual override is toggled (via shortcut or system change).
     void OnManualOverride();
 
+    // Called when night light changes in windows settings
+    void OnNightLightChange();
+
     // Initial sync at startup to align internal state with system theme
     void SyncInitialThemeState();
 

src/modules/LightSwitch/LightSwitchService/NightLightRegistryObserver.cpp

@@ -0,0 +1 @@
+#include "NightLightRegistryObserver.h"

src/modules/LightSwitch/LightSwitchService/NightLightRegistryObserver.h

@@ -0,0 +1,134 @@
+#pragma once
+#include <wtypes.h>
+#include <string>
+#include <functional>
+#include <thread>
+#include <atomic>
+#include <mutex>
+
+class NightLightRegistryObserver
+{
+public:
+    NightLightRegistryObserver(HKEY root, const std::wstring& subkey, std::function<void()> callback) :
+        _root(root), _subkey(subkey), _callback(std::move(callback)), _stop(false)
+    {
+        _thread = std::thread([this]() { this->Run(); });
+    }
+
+    ~NightLightRegistryObserver()
+    {
+        Stop();
+    }
+
+    void Stop()
+    {
+        _stop = true;
+
+        {
+            std::lock_guard<std::mutex> lock(_mutex);
+            if (_event)
+                SetEvent(_event);
+        }
+
+        if (_thread.joinable())
+            _thread.join();
+
+        std::lock_guard<std::mutex> lock(_mutex);
+        if (_hKey)
+        {
+            RegCloseKey(_hKey);
+            _hKey = nullptr;
+        }
+
+        if (_event)
+        {
+            CloseHandle(_event);
+            _event = nullptr;
+        }
+    }
+
+
+private:
+    void Run()
+    {
+        {
+            std::lock_guard<std::mutex> lock(_mutex);
+            if (RegOpenKeyExW(_root, _subkey.c_str(), 0, KEY_NOTIFY, &_hKey) != ERROR_SUCCESS)
+                return;
+
+            _event = CreateEventW(nullptr, TRUE, FALSE, nullptr);
+            if (!_event)
+            {
+                RegCloseKey(_hKey);
+                _hKey = nullptr;
+                return;
+            }
+        }
+
+        while (!_stop)
+        {
+            HKEY hKeyLocal = nullptr;
+            HANDLE eventLocal = nullptr;
+
+            {
+                std::lock_guard<std::mutex> lock(_mutex);
+                if (_stop)
+                    break;
+
+                hKeyLocal = _hKey;
+                eventLocal = _event;
+            }
+
+            if (!hKeyLocal || !eventLocal)
+                break;
+
+            if (_stop)
+                break;
+
+            if (RegNotifyChangeKeyValue(hKeyLocal, FALSE, REG_NOTIFY_CHANGE_LAST_SET, eventLocal, TRUE) != ERROR_SUCCESS)
+                break;
+
+            DWORD wait = WaitForSingleObject(eventLocal, INFINITE);
+            if (_stop || wait == WAIT_FAILED)
+                break;
+
+            ResetEvent(eventLocal);
+
+            if (!_stop && _callback)
+            {
+                try
+                {
+                    _callback();
+                }
+                catch (...)
+                {
+                }
+            }
+        }
+
+        {
+            std::lock_guard<std::mutex> lock(_mutex);
+            if (_hKey)
+            {
+                RegCloseKey(_hKey);
+                _hKey = nullptr;
+            }
+
+            if (_event)
+            {
+                CloseHandle(_event);
+                _event = nullptr;
+            }
+        }
+    }
+
+
+    HKEY _root;
+    std::wstring _subkey;
+    std::function<void()> _callback;
+    HANDLE _event = nullptr;
+    HKEY _hKey = nullptr;
+    std::thread _thread;
+    std::atomic<bool> _stop;
+    std::mutex _mutex;
+};

src/modules/LightSwitch/LightSwitchService/SettingsConstants.h

@@ -11,4 +11,7 @@ enum class SettingId
     Sunset_Offset,
     ChangeSystem,
     ChangeApps
-};
+};
+
+constexpr wchar_t PERSONALIZATION_REGISTRY_PATH[] = L"Software\\Microsoft\\Windows\\CurrentVersion\\Themes\\Personalize";
+constexpr wchar_t NIGHT_LIGHT_REGISTRY_PATH[] = L"Software\\Microsoft\\Windows\\CurrentVersion\\CloudStore\\Store\\DefaultAccount\\Current\\default$windows.data.bluelightreduction.bluelightreductionstate\\windows.data.bluelightreduction.bluelightreductionstate";

src/modules/LightSwitch/LightSwitchService/ThemeHelper.cpp

@@ -3,6 +3,7 @@
 #include <logger/logger.h>
 #include <utils/logger_helper.h>
 #include "ThemeHelper.h"
+#include <SettingsConstants.h>
 
 // Controls changing the themes.
 
@@ -10,7 +11,7 @@ static void ResetColorPrevalence()
 {
     HKEY hKey;
     if (RegOpenKeyEx(HKEY_CURRENT_USER,
-                     L"Software\\Microsoft\\Windows\\CurrentVersion\\Themes\\Personalize",
+                     PERSONALIZATION_REGISTRY_PATH,
                      0,
                      KEY_SET_VALUE,
                      &hKey) == ERROR_SUCCESS)
@@ -31,7 +32,7 @@ void SetAppsTheme(bool mode)
 {
     HKEY hKey;
     if (RegOpenKeyEx(HKEY_CURRENT_USER,
-                     L"Software\\Microsoft\\Windows\\CurrentVersion\\Themes\\Personalize",
+                     PERSONALIZATION_REGISTRY_PATH,
                      0,
                      KEY_SET_VALUE,
                      &hKey) == ERROR_SUCCESS)
@@ -50,7 +51,7 @@ void SetSystemTheme(bool mode)
 {
     HKEY hKey;
     if (RegOpenKeyEx(HKEY_CURRENT_USER,
-                     L"Software\\Microsoft\\Windows\\CurrentVersion\\Themes\\Personalize",
+                     PERSONALIZATION_REGISTRY_PATH,
                      0,
                      KEY_SET_VALUE,
                      &hKey) == ERROR_SUCCESS)
@@ -79,7 +80,7 @@ bool GetCurrentSystemTheme()
     DWORD size = sizeof(value);
 
     if (RegOpenKeyEx(HKEY_CURRENT_USER,
-                     L"Software\\Microsoft\\Windows\\CurrentVersion\\Themes\\Personalize",
+                     PERSONALIZATION_REGISTRY_PATH,
                      0,
                      KEY_READ,
                      &hKey) == ERROR_SUCCESS)
@@ -98,7 +99,7 @@ bool GetCurrentAppsTheme()
     DWORD size = sizeof(value);
 
     if (RegOpenKeyEx(HKEY_CURRENT_USER,
-                     L"Software\\Microsoft\\Windows\\CurrentVersion\\Themes\\Personalize",
+                     PERSONALIZATION_REGISTRY_PATH,
                      0,
                      KEY_READ,
                      &hKey) == ERROR_SUCCESS)
@@ -109,3 +110,30 @@ bool GetCurrentAppsTheme()
 
     return value == 1; // true = light, false = dark
 }
+
+bool IsNightLightEnabled()
+{
+    HKEY hKey;
+    const wchar_t* path = NIGHT_LIGHT_REGISTRY_PATH;
+
+    if (RegOpenKeyExW(HKEY_CURRENT_USER, path, 0, KEY_READ, &hKey) != ERROR_SUCCESS)
+        return false;
+
+    // RegGetValueW will set size to the size of the data and we expect that to be at least 25 bytes (we need to access bytes 23 and 24)
+    DWORD size = 0;
+    if (RegGetValueW(hKey, nullptr, L"Data", RRF_RT_REG_BINARY, nullptr, nullptr, &size) != ERROR_SUCCESS || size < 25)
+    {
+        RegCloseKey(hKey);
+        return false;
+    }
+
+    std::vector<BYTE> data(size);
+    if (RegGetValueW(hKey, nullptr, L"Data", RRF_RT_REG_BINARY, nullptr, data.data(), &size) != ERROR_SUCCESS)
+    {
+        RegCloseKey(hKey);
+        return false;
+    }
+
+    RegCloseKey(hKey);
+    return data[23] == 0x10 && data[24] == 0x00;
+}

src/modules/LightSwitch/LightSwitchService/ThemeHelper.h

@@ -3,3 +3,4 @@ void SetSystemTheme(bool dark);
 void SetAppsTheme(bool dark);
 bool GetCurrentSystemTheme();
 bool GetCurrentAppsTheme();
+bool IsNightLightEnabled();

src/modules/MouseUtils/MouseUtils.UITests/FindMyMouseTests.cs

@@ -617,6 +617,8 @@ namespace MouseUtils.UITests
 
         private void LaunchFromSetting(bool reload = false, bool launchAsAdmin = false)
         {
+            Session = RestartScopeExe("FindMyMouse,MouseHighlighter,MouseJump,MousePointerCrosshairs,CursorWrap");
+
             // this.Session.Attach(PowerToysModule.PowerToysSettings);
             this.Session.SetMainWindowSize(WindowSize.Large);
 

src/modules/cmdpal/Core/Microsoft.CmdPal.Core.ViewModels/DetailsViewModel.cs

@@ -19,6 +19,8 @@ public partial class DetailsViewModel(IDetails _details, WeakReference<IPageCont
 
     public string Body { get; private set; } = string.Empty;
 
+    public ContentSize? Size { get; private set; } = ContentSize.Small;
+
     // Metadata is an array of IDetailsElement,
     //   where IDetailsElement = {IDetailsTags, IDetailsLink, IDetailsSeparator}
     public List<DetailsElementViewModel> Metadata { get; private set; } = [];
@@ -40,6 +42,21 @@ public partial class DetailsViewModel(IDetails _details, WeakReference<IPageCont
         UpdateProperty(nameof(Body));
         UpdateProperty(nameof(HeroImage));
 
+        if (model is IExtendedAttributesProvider provider)
+        {
+            if (provider.GetProperties()?.TryGetValue("Size", out var rawValue) == true)
+            {
+                if (rawValue is int sizeAsInt)
+                {
+                    Size = (ContentSize)sizeAsInt;
+                }
+            }
+        }
+
+        Size ??= ContentSize.Small;
+
+        UpdateProperty(nameof(Size));
+
         var meta = model.Metadata;
         if (meta is not null)
         {

src/modules/cmdpal/Core/Microsoft.CmdPal.Core.ViewModels/ShellViewModel.cs

@@ -14,6 +14,7 @@ using Microsoft.CommandPalette.Extensions;
 namespace Microsoft.CmdPal.Core.ViewModels;
 
 public partial class ShellViewModel : ObservableObject,
+    IDisposable,
     IRecipient<PerformCommandMessage>,
     IRecipient<HandleCommandResultMessage>
 {
@@ -460,4 +461,12 @@ public partial class ShellViewModel : ObservableObject,
     {
         _navigationCts?.Cancel();
     }
+
+    public void Dispose()
+    {
+        _handleInvokeTask?.Dispose();
+        _navigationCts?.Dispose();
+
+        GC.SuppressFinalize(this);
+    }
 }

src/modules/cmdpal/Microsoft.CmdPal.UI.ViewModels/AppearanceSettingsViewModel.cs

@@ -0,0 +1,390 @@
+// Copyright (c) Microsoft Corporation
+// The Microsoft Corporation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System.Collections.ObjectModel;
+using CommunityToolkit.Mvvm.ComponentModel;
+using CommunityToolkit.Mvvm.Input;
+using CommunityToolkit.WinUI;
+using Microsoft.CmdPal.UI.ViewModels.Services;
+using Microsoft.UI;
+using Microsoft.UI.Dispatching;
+using Microsoft.UI.Xaml;
+using Microsoft.UI.Xaml.Media;
+using Windows.UI;
+using Windows.UI.ViewManagement;
+
+namespace Microsoft.CmdPal.UI.ViewModels;
+
+public sealed partial class AppearanceSettingsViewModel : ObservableObject, IDisposable
+{
+    private static readonly ObservableCollection<Color> WindowsColorSwatches = [
+
+        // row 0
+        Color.FromArgb(255, 255, 185, 0), // #ffb900
+        Color.FromArgb(255, 255, 140, 0), // #ff8c00
+        Color.FromArgb(255, 247, 99, 12), // #f7630c
+        Color.FromArgb(255, 202, 80, 16), // #ca5010
+        Color.FromArgb(255, 218, 59, 1), // #da3b01
+        Color.FromArgb(255, 239, 105, 80), // #ef6950
+
+        // row 1
+        Color.FromArgb(255, 209, 52, 56), // #d13438
+        Color.FromArgb(255, 255, 67, 67), // #ff4343
+        Color.FromArgb(255, 231, 72, 86), // #e74856
+        Color.FromArgb(255, 232, 17, 35), // #e81123
+        Color.FromArgb(255, 234, 0, 94), // #ea005e
+        Color.FromArgb(255, 195, 0, 82), // #c30052
+
+        // row 2
+        Color.FromArgb(255, 227, 0, 140), // #e3008c
+        Color.FromArgb(255, 191, 0, 119), // #bf0077
+        Color.FromArgb(255, 194, 57, 179), // #c239b3
+        Color.FromArgb(255, 154, 0, 137), // #9a0089
+        Color.FromArgb(255, 0, 120, 212), // #0078d4
+        Color.FromArgb(255, 0, 99, 177), // #0063b1
+
+        // row 3
+        Color.FromArgb(255, 142, 140, 216), // #8e8cd8
+        Color.FromArgb(255, 107, 105, 214), // #6b69d6
+        Color.FromArgb(255, 135, 100, 184), // #8764b8
+        Color.FromArgb(255, 116, 77, 169), // #744da9
+        Color.FromArgb(255, 177, 70, 194), // #b146c2
+        Color.FromArgb(255, 136, 23, 152), // #881798
+
+        // row 4
+        Color.FromArgb(255, 0, 153, 188), // #0099bc
+        Color.FromArgb(255, 45, 125, 154), // #2d7d9a
+        Color.FromArgb(255, 0, 183, 195), // #00b7c3
+        Color.FromArgb(255, 3, 131, 135), // #038387
+        Color.FromArgb(255, 0, 178, 148), // #00b294
+        Color.FromArgb(255, 1, 133, 116), // #018574
+
+        // row 5
+        Color.FromArgb(255, 0, 204, 106), // #00cc6a
+        Color.FromArgb(255, 16, 137, 62), // #10893e
+        Color.FromArgb(255, 122, 117, 116), // #7a7574
+        Color.FromArgb(255, 93, 90, 88), // #5d5a58
+        Color.FromArgb(255, 104, 118, 138), // #68768a
+        Color.FromArgb(255, 81, 92, 107), // #515c6b
+
+        // row 6
+        Color.FromArgb(255, 86, 124, 115), // #567c73
+        Color.FromArgb(255, 72, 104, 96), // #486860
+        Color.FromArgb(255, 73, 130, 5), // #498205
+        Color.FromArgb(255, 16, 124, 16), // #107c10
+        Color.FromArgb(255, 118, 118, 118), // #767676
+        Color.FromArgb(255, 76, 74, 72), // #4c4a48
+
+        // row 7
+        Color.FromArgb(255, 105, 121, 126), // #69797e
+        Color.FromArgb(255, 74, 84, 89), // #4a5459
+        Color.FromArgb(255, 100, 124, 100), // #647c64
+        Color.FromArgb(255, 82, 94, 84), // #525e54
+        Color.FromArgb(255, 132, 117, 69), // #847545
+        Color.FromArgb(255, 126, 115, 95), // #7e735f
+    ];
+
+    private readonly SettingsModel _settings;
+    private readonly UISettings _uiSettings;
+    private readonly IThemeService _themeService;
+    private readonly DispatcherQueueTimer _saveTimer = DispatcherQueue.GetForCurrentThread().CreateTimer();
+    private readonly DispatcherQueue _uiDispatcher = DispatcherQueue.GetForCurrentThread();
+
+    private ElementTheme? _elementThemeOverride;
+    private Color _currentSystemAccentColor;
+
+    public ObservableCollection<Color> Swatches => WindowsColorSwatches;
+
+    public int ThemeIndex
+    {
+        get => (int)_settings.Theme;
+        set => Theme = (UserTheme)value;
+    }
+
+    public UserTheme Theme
+    {
+        get => _settings.Theme;
+        set
+        {
+            if (_settings.Theme != value)
+            {
+                _settings.Theme = value;
+                OnPropertyChanged();
+                OnPropertyChanged(nameof(ThemeIndex));
+                Save();
+            }
+        }
+    }
+
+    public ColorizationMode ColorizationMode
+    {
+        get => _settings.ColorizationMode;
+        set
+        {
+            if (_settings.ColorizationMode != value)
+            {
+                _settings.ColorizationMode = value;
+                OnPropertyChanged();
+                OnPropertyChanged(nameof(ColorizationModeIndex));
+                OnPropertyChanged(nameof(IsCustomTintVisible));
+                OnPropertyChanged(nameof(IsCustomTintIntensityVisible));
+                OnPropertyChanged(nameof(IsBackgroundControlsVisible));
+                OnPropertyChanged(nameof(IsNoBackgroundVisible));
+                OnPropertyChanged(nameof(IsAccentColorControlsVisible));
+
+                if (value == ColorizationMode.WindowsAccentColor)
+                {
+                    ThemeColor = _currentSystemAccentColor;
+                }
+
+                IsColorizationDetailsExpanded = value != ColorizationMode.None;
+
+                Save();
+            }
+        }
+    }
+
+    public int ColorizationModeIndex
+    {
+        get => (int)_settings.ColorizationMode;
+        set => ColorizationMode = (ColorizationMode)value;
+    }
+
+    public Color ThemeColor
+    {
+        get => _settings.CustomThemeColor;
+        set
+        {
+            if (_settings.CustomThemeColor != value)
+            {
+                _settings.CustomThemeColor = value;
+
+                OnPropertyChanged();
+
+                if (ColorIntensity == 0)
+                {
+                    ColorIntensity = 100;
+                }
+
+                Save();
+            }
+        }
+    }
+
+    public int ColorIntensity
+    {
+        get => _settings.CustomThemeColorIntensity;
+        set
+        {
+            _settings.CustomThemeColorIntensity = value;
+            OnPropertyChanged();
+            Save();
+        }
+    }
+
+    public string BackgroundImagePath
+    {
+        get => _settings.BackgroundImagePath ?? string.Empty;
+        set
+        {
+            if (_settings.BackgroundImagePath != value)
+            {
+                _settings.BackgroundImagePath = value;
+                OnPropertyChanged();
+
+                if (BackgroundImageOpacity == 0)
+                {
+                    BackgroundImageOpacity = 100;
+                }
+
+                Save();
+            }
+        }
+    }
+
+    public int BackgroundImageOpacity
+    {
+        get => _settings.BackgroundImageOpacity;
+        set
+        {
+            if (_settings.BackgroundImageOpacity != value)
+            {
+                _settings.BackgroundImageOpacity = value;
+                OnPropertyChanged();
+                Save();
+            }
+        }
+    }
+
+    public int BackgroundImageBrightness
+    {
+        get => _settings.BackgroundImageBrightness;
+        set
+        {
+            if (_settings.BackgroundImageBrightness != value)
+            {
+                _settings.BackgroundImageBrightness = value;
+                OnPropertyChanged();
+                Save();
+            }
+        }
+    }
+
+    public int BackgroundImageBlurAmount
+    {
+        get => _settings.BackgroundImageBlurAmount;
+        set
+        {
+            if (_settings.BackgroundImageBlurAmount != value)
+            {
+                _settings.BackgroundImageBlurAmount = value;
+                OnPropertyChanged();
+                Save();
+            }
+        }
+    }
+
+    public BackgroundImageFit BackgroundImageFit
+    {
+        get => _settings.BackgroundImageFit;
+        set
+        {
+            if (_settings.BackgroundImageFit != value)
+            {
+                _settings.BackgroundImageFit = value;
+                OnPropertyChanged();
+                OnPropertyChanged(nameof(BackgroundImageFitIndex));
+                Save();
+            }
+        }
+    }
+
+    public int BackgroundImageFitIndex
+    {
+        // Naming between UI facing string and enum is a bit confusing, but the enum fields
+        // are based on XAML Stretch enum values. So I'm choosing to keep the confusion here, close
+        // to the UI.
+        // - BackgroundImageFit.Fill corresponds to "Stretch"
+        // - BackgroundImageFit.UniformToFill corresponds to "Fill"
+        get => BackgroundImageFit switch
+        {
+            BackgroundImageFit.Fill => 1,
+            _ => 0,
+        };
+        set => BackgroundImageFit = value switch
+        {
+            1 => BackgroundImageFit.Fill,
+            _ => BackgroundImageFit.UniformToFill,
+        };
+    }
+
+    [ObservableProperty]
+    public partial bool IsColorizationDetailsExpanded { get; set; }
+
+    public bool IsCustomTintVisible => _settings.ColorizationMode is ColorizationMode.CustomColor or ColorizationMode.Image;
+
+    public bool IsCustomTintIntensityVisible => _settings.ColorizationMode is ColorizationMode.CustomColor or ColorizationMode.WindowsAccentColor or ColorizationMode.Image;
+
+    public bool IsBackgroundControlsVisible => _settings.ColorizationMode is ColorizationMode.Image;
+
+    public bool IsNoBackgroundVisible => _settings.ColorizationMode is ColorizationMode.None;
+
+    public bool IsAccentColorControlsVisible => _settings.ColorizationMode is ColorizationMode.WindowsAccentColor;
+
+    public AcrylicBackdropParameters EffectiveBackdrop { get; private set; } = new(Colors.Black, Colors.Black, 0.5f, 0.5f);
+
+    public ElementTheme EffectiveTheme => _elementThemeOverride ?? _themeService.Current.Theme;
+
+    public Color EffectiveThemeColor => ColorizationMode switch
+    {
+        ColorizationMode.WindowsAccentColor => _currentSystemAccentColor,
+        ColorizationMode.CustomColor or ColorizationMode.Image => ThemeColor,
+        _ => Colors.Transparent,
+    };
+
+    // Since the blur amount is absolute, we need to scale it down for the preview (which is smaller than full screen).
+    public int EffectiveBackgroundImageBlurAmount => (int)Math.Round(BackgroundImageBlurAmount / 4f);
+
+    public double EffectiveBackgroundImageBrightness => BackgroundImageBrightness / 100.0;
+
+    public ImageSource? EffectiveBackgroundImageSource =>
+        ColorizationMode is ColorizationMode.Image
+        && !string.IsNullOrWhiteSpace(BackgroundImagePath)
+        && Uri.TryCreate(BackgroundImagePath, UriKind.RelativeOrAbsolute, out var uri)
+            ? new Microsoft.UI.Xaml.Media.Imaging.BitmapImage(uri)
+            : null;
+
+    public AppearanceSettingsViewModel(IThemeService themeService, SettingsModel settings)
+    {
+        _themeService = themeService;
+        _themeService.ThemeChanged += ThemeServiceOnThemeChanged;
+        _settings = settings;
+
+        _uiSettings = new UISettings();
+        _uiSettings.ColorValuesChanged += UiSettingsOnColorValuesChanged;
+        UpdateAccentColor(_uiSettings);
+
+        Reapply();
+
+        IsColorizationDetailsExpanded = _settings.ColorizationMode != ColorizationMode.None;
+    }
+
+    private void UiSettingsOnColorValuesChanged(UISettings sender, object args) => _uiDispatcher.TryEnqueue(() => UpdateAccentColor(sender));
+
+    private void UpdateAccentColor(UISettings sender)
+    {
+        _currentSystemAccentColor = sender.GetColorValue(UIColorType.Accent);
+        if (ColorizationMode == ColorizationMode.WindowsAccentColor)
+        {
+            ThemeColor = _currentSystemAccentColor;
+        }
+    }
+
+    private void ThemeServiceOnThemeChanged(object? sender, ThemeChangedEventArgs e)
+    {
+        _saveTimer.Debounce(Reapply, TimeSpan.FromMilliseconds(200));
+    }
+
+    private void Save()
+    {
+        SettingsModel.SaveSettings(_settings);
+        _saveTimer.Debounce(Reapply, TimeSpan.FromMilliseconds(200));
+    }
+
+    private void Reapply()
+    {
+        // Theme services recalculates effective color and opacity based on current settings.
+        EffectiveBackdrop = _themeService.Current.BackdropParameters;
+        OnPropertyChanged(nameof(EffectiveBackdrop));
+        OnPropertyChanged(nameof(EffectiveBackgroundImageBrightness));
+        OnPropertyChanged(nameof(EffectiveBackgroundImageSource));
+        OnPropertyChanged(nameof(EffectiveThemeColor));
+        OnPropertyChanged(nameof(EffectiveBackgroundImageBlurAmount));
+
+        // LOAD BEARING:
+        // We need to cycle through the EffectiveTheme property to force reload of resources.
+        _elementThemeOverride = ElementTheme.Light;
+        OnPropertyChanged(nameof(EffectiveTheme));
+        _elementThemeOverride = ElementTheme.Dark;
+        OnPropertyChanged(nameof(EffectiveTheme));
+        _elementThemeOverride = null;
+        OnPropertyChanged(nameof(EffectiveTheme));
+    }
+
+    [RelayCommand]
+    private void ResetBackgroundImageProperties()
+    {
+        BackgroundImageBrightness = 0;
+        BackgroundImageBlurAmount = 0;
+        BackgroundImageFit = BackgroundImageFit.UniformToFill;
+        BackgroundImageOpacity = 100;
+        ColorIntensity = 0;
+    }
+
+    public void Dispose()
+    {
+        _uiSettings.ColorValuesChanged -= UiSettingsOnColorValuesChanged;
+        _themeService.ThemeChanged -= ThemeServiceOnThemeChanged;
+    }
+}

src/modules/cmdpal/Microsoft.CmdPal.UI.ViewModels/BackgroundImageFit.cs

@@ -0,0 +1,11 @@
+// Copyright (c) Microsoft Corporation
+// The Microsoft Corporation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+namespace Microsoft.CmdPal.UI.ViewModels;
+
+public enum BackgroundImageFit
+{
+    Fill,
+    UniformToFill,
+}

src/modules/cmdpal/Microsoft.CmdPal.UI.ViewModels/ColorizationMode.cs

@@ -0,0 +1,13 @@
+// Copyright (c) Microsoft Corporation
+// The Microsoft Corporation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+namespace Microsoft.CmdPal.UI.ViewModels;
+
+public enum ColorizationMode
+{
+    None,
+    WindowsAccentColor,
+    CustomColor,
+    Image,
+}

src/modules/cmdpal/Microsoft.CmdPal.UI.ViewModels/Commands/MainListPage.cs

@@ -12,6 +12,7 @@ using Microsoft.CmdPal.Core.ViewModels.Messages;
 using Microsoft.CmdPal.Ext.Apps;
 using Microsoft.CmdPal.Ext.Apps.Programs;
 using Microsoft.CmdPal.Ext.Apps.State;
+using Microsoft.CmdPal.UI.ViewModels.Commands;
 using Microsoft.CmdPal.UI.ViewModels.Messages;
 using Microsoft.CmdPal.UI.ViewModels.Properties;
 using Microsoft.CommandPalette.Extensions;
@@ -33,7 +34,10 @@ public partial class MainListPage : DynamicListPage,
     private readonly AppStateModel _appStateModel;
     private List<Scored<IListItem>>? _filteredItems;
     private List<Scored<IListItem>>? _filteredApps;
-    private IEnumerable<Scored<IListItem>>? _fallbackItems;
+    private List<Scored<IListItem>>? _fallbackItems;
+
+    // Keep as IEnumerable for deferred execution. Fallback item titles are updated
+    // asynchronously, so scoring must happen lazily when GetItems is called.
     private IEnumerable<Scored<IListItem>>? _scoredFallbackItems;
     private bool _includeApps;
     private bool _filteredItemsIncludesApps;
@@ -146,44 +150,24 @@ public partial class MainListPage : DynamicListPage,
 
     public override IListItem[] GetItems()
     {
-        if (string.IsNullOrEmpty(SearchText))
+        lock (_tlcManager.TopLevelCommands)
         {
-            lock (_tlcManager.TopLevelCommands)
+            // Either return the top-level commands (no search text), or the merged and
+            // filtered results.
+            if (string.IsNullOrWhiteSpace(SearchText))
             {
-                return _tlcManager
-                    .TopLevelCommands
+                return _tlcManager.TopLevelCommands
                     .Where(tlc => !tlc.IsFallback && !string.IsNullOrEmpty(tlc.Title))
                     .ToArray();
             }
-        }
-        else
-        {
-            lock (_tlcManager.TopLevelCommands)
+            else
             {
-                var limitedApps = new List<Scored<IListItem>>();
-
-                // Fuzzy matching can produce a lot of results, so we want to limit the
-                // number of apps we show at once if it's a large set.
-                if (_filteredApps?.Count > 0)
-                {
-                    limitedApps = _filteredApps.OrderByDescending(s => s.Score).Take(_appResultLimit).ToList();
-                }
-
-                var orderedFallbacks = _fallbackItems?
-                    .Where(w => !string.IsNullOrEmpty(w.Item.Title))
-                    .OrderByDescending(o => o.Score).ToList();
-
-                var items = Enumerable.Empty<Scored<IListItem>>()
-                                .Concat(_filteredItems is not null ? _filteredItems : [])
-                                .Concat(_scoredFallbackItems is not null ? _scoredFallbackItems : [])
-                                .Concat(limitedApps)
-                                .OrderByDescending(o => o.Score)
-
-                                // Now append the fallbacks that weren't scored (because they weren't in the global fallbacks list)
-                                .Concat(orderedFallbacks ?? [])
-                                .Select(s => s.Item)
-                                .ToArray();
-                return items;
+                return MainListPageResultFactory.Create(
+                    _filteredItems,
+                    _scoredFallbackItems?.ToList(),
+                    _filteredApps,
+                    _fallbackItems,
+                    _appResultLimit);
             }
         }
     }
@@ -402,15 +386,8 @@ public partial class MainListPage : DynamicListPage,
                 return;
             }
 
-            _scoredFallbackItems = ListHelpers.FilterListWithScores<IListItem>(newFallbacksForScoring ?? [], SearchText, scoreItem);
-
-            if (token.IsCancellationRequested)
-            {
-                return;
-            }
-
             Func<string, IListItem, int> scoreFallbackItem = (a, b) => { return ScoreFallbackItem(a, b, _settings.FallbackRanks); };
-            _fallbackItems = ListHelpers.FilterListWithScores<IListItem>(newFallbacks ?? [], SearchText, scoreFallbackItem);
+            _fallbackItems = [.. ListHelpers.FilterListWithScores<IListItem>(newFallbacks ?? [], SearchText, scoreFallbackItem)];
 
             if (token.IsCancellationRequested)
             {

src/modules/cmdpal/Microsoft.CmdPal.UI.ViewModels/Commands/MainListPageResultFactory.cs

@@ -0,0 +1,156 @@
+// Copyright (c) Microsoft Corporation
+// The Microsoft Corporation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+#pragma warning disable IDE0007 // Use implicit type
+
+using Microsoft.CommandPalette.Extensions;
+using Microsoft.CommandPalette.Extensions.Toolkit;
+
+namespace Microsoft.CmdPal.UI.ViewModels.Commands;
+
+internal static class MainListPageResultFactory
+{
+    /// <summary>
+    /// Creates a merged and ordered array of results from multiple scored input lists,
+    /// applying an application result limit and filtering fallback items as needed.
+    /// </summary>
+    public static IListItem[] Create(
+        IList<Scored<IListItem>>? filteredItems,
+        IList<Scored<IListItem>>? scoredFallbackItems,
+        IList<Scored<IListItem>>? filteredApps,
+        IList<Scored<IListItem>>? fallbackItems,
+        int appResultLimit)
+    {
+        if (appResultLimit < 0)
+        {
+            throw new ArgumentOutOfRangeException(
+                nameof(appResultLimit), "App result limit must be non-negative.");
+        }
+
+        int len1 = filteredItems?.Count ?? 0;
+        int len2 = scoredFallbackItems?.Count ?? 0;
+
+        // Apps are pre-sorted, so we just need to take the top N, limited by appResultLimit.
+        int len3 = Math.Min(filteredApps?.Count ?? 0, appResultLimit);
+
+        // Allocate the exact size of the result array.
+        int totalCount = len1 + len2 + len3 + GetNonEmptyFallbackItemsCount(fallbackItems);
+        var result = new IListItem[totalCount];
+
+        // Three-way stable merge of already-sorted lists.
+        int idx1 = 0, idx2 = 0, idx3 = 0;
+        int writePos = 0;
+
+        // Merge while all three lists have items. To maintain a stable sort, the
+        // priority is: list1 > list2 > list3 when scores are equal.
+        while (idx1 < len1 && idx2 < len2 && idx3 < len3)
+        {
+            // Using null-forgiving operator as we have already checked against lengths.
+            int score1 = filteredItems![idx1].Score;
+            int score2 = scoredFallbackItems![idx2].Score;
+            int score3 = filteredApps![idx3].Score;
+
+            if (score1 >= score2 && score1 >= score3)
+            {
+                result[writePos++] = filteredItems[idx1++].Item;
+            }
+            else if (score2 >= score3)
+            {
+                result[writePos++] = scoredFallbackItems[idx2++].Item;
+            }
+            else
+            {
+                result[writePos++] = filteredApps[idx3++].Item;
+            }
+        }
+
+        // Two-way merges for remaining pairs.
+        while (idx1 < len1 && idx2 < len2)
+        {
+            if (filteredItems![idx1].Score >= scoredFallbackItems![idx2].Score)
+            {
+                result[writePos++] = filteredItems[idx1++].Item;
+            }
+            else
+            {
+                result[writePos++] = scoredFallbackItems[idx2++].Item;
+            }
+        }
+
+        while (idx1 < len1 && idx3 < len3)
+        {
+            if (filteredItems![idx1].Score >= filteredApps![idx3].Score)
+            {
+                result[writePos++] = filteredItems[idx1++].Item;
+            }
+            else
+            {
+                result[writePos++] = filteredApps[idx3++].Item;
+            }
+        }
+
+        while (idx2 < len2 && idx3 < len3)
+        {
+            if (scoredFallbackItems![idx2].Score >= filteredApps![idx3].Score)
+            {
+                result[writePos++] = scoredFallbackItems[idx2++].Item;
+            }
+            else
+            {
+                result[writePos++] = filteredApps[idx3++].Item;
+            }
+        }
+
+        // Drain remaining items from a non-empty list.
+        while (idx1 < len1)
+        {
+            result[writePos++] = filteredItems![idx1++].Item;
+        }
+
+        while (idx2 < len2)
+        {
+            result[writePos++] = scoredFallbackItems![idx2++].Item;
+        }
+
+        while (idx3 < len3)
+        {
+            result[writePos++] = filteredApps![idx3++].Item;
+        }
+
+        // Append filtered fallback items. Fallback items are added post-sort so they are
+        // always at the end of the list and are sorted by user settings.
+        if (fallbackItems is not null)
+        {
+            for (int i = 0; i < fallbackItems.Count; i++)
+            {
+                var item = fallbackItems[i].Item;
+                if (!string.IsNullOrEmpty(item.Title))
+                {
+                    result[writePos++] = item;
+                }
+            }
+        }
+
+        return result;
+    }
+
+    private static int GetNonEmptyFallbackItemsCount(IList<Scored<IListItem>>? fallbackItems)
+    {
+        int fallbackItemsCount = 0;
+
+        if (fallbackItems is not null)
+        {
+            for (int i = 0; i < fallbackItems.Count; i++)
+            {
+                if (!string.IsNullOrEmpty(fallbackItems[i].Item.Title))
+                {
+                    fallbackItemsCount++;
+                }
+            }
+        }
+
+        return fallbackItemsCount;
+    }
+}
+#pragma warning restore IDE0007 // Use implicit type

src/modules/cmdpal/Microsoft.CmdPal.UI.ViewModels/MainWindowViewModel.cs

@@ -0,0 +1,70 @@
+// Copyright (c) Microsoft Corporation
+// The Microsoft Corporation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using CommunityToolkit.Mvvm.ComponentModel;
+using Microsoft.CmdPal.UI.ViewModels.Services;
+using Microsoft.UI.Dispatching;
+using Microsoft.UI.Xaml.Media;
+using Windows.UI;
+
+namespace Microsoft.CmdPal.UI.ViewModels;
+
+public partial class MainWindowViewModel : ObservableObject, IDisposable
+{
+    private readonly IThemeService _themeService;
+    private readonly DispatcherQueue _uiDispatcherQueue = DispatcherQueue.GetForCurrentThread()!;
+
+    [ObservableProperty]
+    public partial ImageSource? BackgroundImageSource { get; private set; }
+
+    [ObservableProperty]
+    public partial Stretch BackgroundImageStretch { get; private set; } = Stretch.Fill;
+
+    [ObservableProperty]
+    public partial double BackgroundImageOpacity { get; private set; }
+
+    [ObservableProperty]
+    public partial Color BackgroundImageTint { get; private set; }
+
+    [ObservableProperty]
+    public partial double BackgroundImageTintIntensity { get; private set; }
+
+    [ObservableProperty]
+    public partial int BackgroundImageBlurAmount { get; private set; }
+
+    [ObservableProperty]
+    public partial double BackgroundImageBrightness { get; private set; }
+
+    [ObservableProperty]
+    public partial bool ShowBackgroundImage { get; private set; }
+
+    public MainWindowViewModel(IThemeService themeService)
+    {
+        _themeService = themeService;
+        _themeService.ThemeChanged += ThemeService_ThemeChanged;
+    }
+
+    private void ThemeService_ThemeChanged(object? sender, ThemeChangedEventArgs e)
+    {
+        _uiDispatcherQueue.TryEnqueue(() =>
+        {
+            BackgroundImageSource = _themeService.Current.BackgroundImageSource;
+            BackgroundImageStretch = _themeService.Current.BackgroundImageStretch;
+            BackgroundImageOpacity = _themeService.Current.BackgroundImageOpacity;
+
+            BackgroundImageBrightness = _themeService.Current.BackgroundBrightness;
+            BackgroundImageTint = _themeService.Current.Tint;
+            BackgroundImageTintIntensity = _themeService.Current.TintIntensity;
+            BackgroundImageBlurAmount = _themeService.Current.BlurAmount;
+
+            ShowBackgroundImage = BackgroundImageSource != null;
+        });
+    }
+
+    public void Dispose()
+    {
+        _themeService.ThemeChanged -= ThemeService_ThemeChanged;
+        GC.SuppressFinalize(this);
+    }
+}

src/modules/cmdpal/Microsoft.CmdPal.UI.ViewModels/Microsoft.CmdPal.UI.ViewModels.csproj

@@ -23,11 +23,12 @@
     <PackageReference Include="CommunityToolkit.Common" />
     <PackageReference Include="CommunityToolkit.Mvvm" />
     <PackageReference Include="AdaptiveCards.Templating" />
+    <PackageReference Include="CommunityToolkit.WinUI.Extensions" />
     <PackageReference Include="Microsoft.Bot.AdaptiveExpressions.Core" />
     <PackageReference Include="AdaptiveCards.ObjectModel.WinUI3" GeneratePathProperty="true">
       <ExcludeAssets>compile</ExcludeAssets>
     </PackageReference>
-    <PackageReference Include="AdaptiveCards.Rendering.WinUI3" GeneratePathProperty="True" >
+    <PackageReference Include="AdaptiveCards.Rendering.WinUI3" GeneratePathProperty="True">
       <ExcludeAssets>compile</ExcludeAssets>
     </PackageReference>
 

src/modules/cmdpal/Microsoft.CmdPal.UI.ViewModels/Properties/Resources.Designer.cs

@@ -19,7 +19,7 @@ namespace Microsoft.CmdPal.UI.ViewModels.Properties {
     // class via a tool like ResGen or Visual Studio.
     // To add or remove a member, edit your .ResX file then rerun ResGen
     // with the /str option, or rebuild your VS project.
-    [global::System.CodeDom.Compiler.GeneratedCodeAttribute("System.Resources.Tools.StronglyTypedResourceBuilder", "17.0.0.0")]
+    [global::System.CodeDom.Compiler.GeneratedCodeAttribute("System.Resources.Tools.StronglyTypedResourceBuilder", "18.0.0.0")]
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
     [global::System.Runtime.CompilerServices.CompilerGeneratedAttribute()]
     public class Resources {
@@ -411,6 +411,15 @@ namespace Microsoft.CmdPal.UI.ViewModels.Properties {
             }
         }
         
+        /// <summary>
+        ///   Looks up a localized string similar to Pick background image.
+        /// </summary>
+        public static string builtin_settings_appearance_pick_background_image_title {
+            get {
+                return ResourceManager.GetString("builtin_settings_appearance_pick_background_image_title", resourceCulture);
+            }
+        }
+        
         /// <summary>
         ///   Looks up a localized string similar to {0} extensions found.
         /// </summary>

src/modules/cmdpal/Microsoft.CmdPal.UI.ViewModels/Properties/Resources.resx

@@ -239,4 +239,7 @@
   <data name="builtin_settings_extension_n_extensions_installed" xml:space="preserve">
     <value>{0} extensions installed</value>
   </data>
+  <data name="builtin_settings_appearance_pick_background_image_title" xml:space="preserve">
+    <value>Pick background image</value>
+  </data>
 </root>

src/modules/cmdpal/Microsoft.CmdPal.UI.ViewModels/Services/AcrylicBackdropParameters.cs

@@ -0,0 +1,9 @@
+// Copyright (c) Microsoft Corporation
+// The Microsoft Corporation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using Windows.UI;
+
+namespace Microsoft.CmdPal.UI.ViewModels.Services;
+
+public sealed record AcrylicBackdropParameters(Color TintColor, Color FallbackColor, float TintOpacity, float LuminosityOpacity);

src/modules/cmdpal/Microsoft.CmdPal.UI.ViewModels/Services/IThemeService.cs

@@ -0,0 +1,39 @@
+// Copyright (c) Microsoft Corporation
+// The Microsoft Corporation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+namespace Microsoft.CmdPal.UI.ViewModels.Services;
+
+/// <summary>
+/// Provides theme-related values for the Command Palette and notifies listeners about
+/// changes that affect visual appearance (theme, tint, background image, and backdrop).
+/// </summary>
+/// <remarks>
+/// Implementations are expected to monitor system/app theme changes and raise
+/// <see cref="ThemeChanged"/> accordingly. Consumers should call <see cref="Initialize"/>
+/// once to hook required sources and then query properties/methods for the current visuals.
+/// </remarks>
+public interface IThemeService
+{
+    /// <summary>
+    /// Occurs when the effective theme or any visual-affecting setting changes.
+    /// </summary>
+    /// <remarks>
+    /// Triggered for changes such as app theme (light/dark/default), background image,
+    /// tint/accent, or backdrop parameters that would require UI to refresh styling.
+    /// </remarks>
+    event EventHandler<ThemeChangedEventArgs>? ThemeChanged;
+
+    /// <summary>
+    /// Initializes the theme service and starts listening for theme-related changes.
+    /// </summary>
+    /// <remarks>
+    /// Safe to call once during application startup before consuming the service.
+    /// </remarks>
+    void Initialize();
+
+    /// <summary>
+    /// Gets the current theme settings.
+    /// </summary>
+    ThemeSnapshot Current { get; }
+}

src/modules/cmdpal/Microsoft.CmdPal.UI.ViewModels/Services/ThemeChangedEventArgs.cs

@@ -0,0 +1,9 @@
+// Copyright (c) Microsoft Corporation
+// The Microsoft Corporation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+namespace Microsoft.CmdPal.UI.ViewModels.Services;
+
+/// <summary>
+/// Event arguments for theme-related changes. </summary>
+public class ThemeChangedEventArgs : EventArgs;

src/modules/cmdpal/Microsoft.CmdPal.UI.ViewModels/Services/ThemeSnapshot.cs

@@ -0,0 +1,62 @@
+// Copyright (c) Microsoft Corporation
+// The Microsoft Corporation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using Microsoft.UI.Xaml;
+using Microsoft.UI.Xaml.Media;
+using Windows.UI;
+
+namespace Microsoft.CmdPal.UI.ViewModels.Services;
+
+/// <summary>
+/// Represents a snapshot of theme-related visual settings, including accent color, theme preference, and background
+/// image configuration, for use in rendering the Command Palette UI.
+/// </summary>
+public sealed class ThemeSnapshot
+{
+    /// <summary>
+    /// Gets the accent tint color used by the Command Palette visuals.
+    /// </summary>
+    public required Color Tint { get; init; }
+
+    /// <summary>
+    /// Gets the accent tint color used by the Command Palette visuals.
+    /// </summary>
+    public required float TintIntensity { get; init; }
+
+    /// <summary>
+    /// Gets the configured application theme preference.
+    /// </summary>
+    public required ElementTheme Theme { get; init; }
+
+    /// <summary>
+    /// Gets the image source to render as the background, if any.
+    /// </summary>
+    /// <remarks>
+    /// Returns <see langword="null"/> when no background image is configured.
+    /// </remarks>
+    public required ImageSource? BackgroundImageSource { get; init; }
+
+    /// <summary>
+    /// Gets the stretch mode used to lay out the background image.
+    /// </summary>
+    public required Stretch BackgroundImageStretch { get; init; }
+
+    /// <summary>
+    /// Gets the opacity applied to the background image.
+    /// </summary>
+    /// <value>
+    /// A value in the range [0, 1], where 0 is fully transparent and 1 is fully opaque.
+    /// </value>
+    public required double BackgroundImageOpacity { get; init; }
+
+    /// <summary>
+    /// Gets the effective acrylic backdrop parameters based on current settings and theme.
+    /// </summary>
+    /// <returns>The resolved <c>AcrylicBackdropParameters</c> to apply.</returns>
+    public required AcrylicBackdropParameters BackdropParameters { get; init; }
+
+    public required int BlurAmount { get; init; }
+
+    public required float BackgroundBrightness { get; init; }
+}

src/modules/cmdpal/Microsoft.CmdPal.UI.ViewModels/SettingsModel.cs

@@ -11,7 +11,9 @@ using CommunityToolkit.Mvvm.ComponentModel;
 using ManagedCommon;
 using Microsoft.CmdPal.UI.ViewModels.Settings;
 using Microsoft.CommandPalette.Extensions.Toolkit;
+using Microsoft.UI;
 using Windows.Foundation;
+using Windows.UI;
 
 namespace Microsoft.CmdPal.UI.ViewModels;
 
@@ -64,6 +66,24 @@ public partial class SettingsModel : ObservableObject
 
     public EscapeKeyBehavior EscapeKeyBehaviorSetting { get; set; } = EscapeKeyBehavior.ClearSearchFirstThenGoBack;
 
+    public UserTheme Theme { get; set; } = UserTheme.Default;
+
+    public ColorizationMode ColorizationMode { get; set; }
+
+    public Color CustomThemeColor { get; set; } = Colors.Transparent;
+
+    public int CustomThemeColorIntensity { get; set; } = 100;
+
+    public int BackgroundImageOpacity { get; set; } = 20;
+
+    public int BackgroundImageBlurAmount { get; set; }
+
+    public int BackgroundImageBrightness { get; set; }
+
+    public BackgroundImageFit BackgroundImageFit { get; set; }
+
+    public string? BackgroundImagePath { get; set; }
+
     // END SETTINGS
     ///////////////////////////////////////////////////////////////////////////
 

src/modules/cmdpal/Microsoft.CmdPal.UI.ViewModels/SettingsViewModel.cs

@@ -4,6 +4,7 @@
 
 using System.Collections.ObjectModel;
 using System.ComponentModel;
+using Microsoft.CmdPal.UI.ViewModels.Services;
 using Microsoft.CmdPal.UI.ViewModels.Settings;
 using Microsoft.CommandPalette.Extensions.Toolkit;
 
@@ -29,6 +30,8 @@ public partial class SettingsViewModel : INotifyPropertyChanged
 
     public event PropertyChangedEventHandler? PropertyChanged;
 
+    public AppearanceSettingsViewModel Appearance { get; }
+
     public HotkeySettings? Hotkey
     {
         get => _settings.Hotkey;
@@ -176,11 +179,13 @@ public partial class SettingsViewModel : INotifyPropertyChanged
 
     public SettingsExtensionsViewModel Extensions { get; }
 
-    public SettingsViewModel(SettingsModel settings, TopLevelCommandManager topLevelCommandManager, TaskScheduler scheduler)
+    public SettingsViewModel(SettingsModel settings, TopLevelCommandManager topLevelCommandManager, TaskScheduler scheduler, IThemeService themeService)
     {
         _settings = settings;
         _topLevelCommandManager = topLevelCommandManager;
 
+        Appearance = new AppearanceSettingsViewModel(themeService, _settings);
+
         var activeProviders = GetCommandProviders();
         var allProviderSettings = _settings.ProviderSettings;
 

src/modules/cmdpal/Microsoft.CmdPal.UI.ViewModels/UserTheme.cs

@@ -0,0 +1,12 @@
+// Copyright (c) Microsoft Corporation
+// The Microsoft Corporation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+namespace Microsoft.CmdPal.UI.ViewModels;
+
+public enum UserTheme
+{
+    Default,
+    Light,
+    Dark,
+}

src/modules/cmdpal/Microsoft.CmdPal.UI/App.xaml

@@ -4,19 +4,23 @@
     xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
     xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
     xmlns:controls="using:Microsoft.CmdPal.UI.Controls"
-    xmlns:local="using:Microsoft.CmdPal.UI">
+    xmlns:local="using:Microsoft.CmdPal.UI"
+    xmlns:services="using:Microsoft.CmdPal.UI.Services">
     <Application.Resources>
         <ResourceDictionary>
             <ResourceDictionary.MergedDictionaries>
                 <XamlControlsResources xmlns="using:Microsoft.UI.Xaml.Controls" />
                 <!--  Other merged dictionaries here  -->
-                <ResourceDictionary Source="Styles/Colors.xaml" />
-                <ResourceDictionary Source="Styles/TextBlock.xaml" />
-                <ResourceDictionary Source="Styles/TextBox.xaml" />
-                <ResourceDictionary Source="Styles/Settings.xaml" />
-                <ResourceDictionary Source="Controls/Tag.xaml" />
-                <ResourceDictionary Source="Controls/KeyVisual/KeyVisual.xaml" />
-                <ResourceDictionary Source="Controls/IsEnabledTextBlock.xaml" />
+                <ResourceDictionary Source="ms-appx:///Styles/Colors.xaml" />
+                <ResourceDictionary Source="ms-appx:///Styles/TextBlock.xaml" />
+                <ResourceDictionary Source="ms-appx:///Styles/TextBox.xaml" />
+                <ResourceDictionary Source="ms-appx:///Styles/Settings.xaml" />
+                <ResourceDictionary Source="ms-appx:///Controls/Tag.xaml" />
+                <ResourceDictionary Source="ms-appx:///Controls/KeyVisual/KeyVisual.xaml" />
+                <ResourceDictionary Source="ms-appx:///Controls/IsEnabledTextBlock.xaml" />
+                <!--  Default theme dictionary  -->
+                <ResourceDictionary Source="ms-appx:///Styles/Theme.Normal.xaml" />
+                <services:MutableOverridesDictionary />
             </ResourceDictionary.MergedDictionaries>
             <!--  Other app resources here  -->
 

src/modules/cmdpal/Microsoft.CmdPal.UI/App.xaml.cs

@@ -24,9 +24,11 @@ using Microsoft.CmdPal.Ext.WindowsTerminal;
 using Microsoft.CmdPal.Ext.WindowWalker;
 using Microsoft.CmdPal.Ext.WinGet;
 using Microsoft.CmdPal.UI.Helpers;
+using Microsoft.CmdPal.UI.Services;
 using Microsoft.CmdPal.UI.ViewModels;
 using Microsoft.CmdPal.UI.ViewModels.BuiltinCommands;
 using Microsoft.CmdPal.UI.ViewModels.Models;
+using Microsoft.CmdPal.UI.ViewModels.Services;
 using Microsoft.CommandPalette.Extensions;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.PowerToys.Telemetry;
@@ -112,6 +114,17 @@ public partial class App : Application
         // Root services
         services.AddSingleton(TaskScheduler.FromCurrentSynchronizationContext());
 
+        AddBuiltInCommands(services);
+
+        AddCoreServices(services);
+
+        AddUIServices(services);
+
+        return services.BuildServiceProvider();
+    }
+
+    private static void AddBuiltInCommands(ServiceCollection services)
+    {
         // Built-in Commands. Order matters - this is the order they'll be presented by default.
         var allApps = new AllAppsCommandProvider();
         var files = new IndexerCommandsProvider();
@@ -154,17 +167,32 @@ public partial class App : Application
         services.AddSingleton<ICommandProvider, TimeDateCommandsProvider>();
         services.AddSingleton<ICommandProvider, SystemCommandExtensionProvider>();
         services.AddSingleton<ICommandProvider, RemoteDesktopCommandProvider>();
+    }
 
+    private static void AddUIServices(ServiceCollection services)
+    {
         // Models
-        services.AddSingleton<TopLevelCommandManager>();
-        services.AddSingleton<AliasManager>();
-        services.AddSingleton<HotkeyManager>();
         var sm = SettingsModel.LoadSettings();
         services.AddSingleton(sm);
         var state = AppStateModel.LoadState();
         services.AddSingleton(state);
-        services.AddSingleton<IExtensionService, ExtensionService>();
+
+        // Services
+        services.AddSingleton<TopLevelCommandManager>();
+        services.AddSingleton<AliasManager>();
+        services.AddSingleton<HotkeyManager>();
+
+        services.AddSingleton<MainWindowViewModel>();
         services.AddSingleton<TrayIconService>();
+
+        services.AddSingleton<IThemeService, ThemeService>();
+        services.AddSingleton<ResourceSwapper>();
+    }
+
+    private static void AddCoreServices(ServiceCollection services)
+    {
+        // Core services
+        services.AddSingleton<IExtensionService, ExtensionService>();
         services.AddSingleton<IRunHistoryService, RunHistoryService>();
 
         services.AddSingleton<IRootPageService, PowerToysRootPageService>();
@@ -174,7 +202,5 @@ public partial class App : Application
         // ViewModels
         services.AddSingleton<ShellViewModel>();
         services.AddSingleton<IPageViewModelFactoryService, CommandPalettePageViewModelFactory>();
-
-        return services.BuildServiceProvider();
     }
 }

src/modules/cmdpal/Microsoft.CmdPal.UI/Controls/BlurImageControl.cs

@@ -0,0 +1,412 @@
+// Copyright (c) Microsoft Corporation
+// The Microsoft Corporation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System.Numerics;
+using ManagedCommon;
+using Microsoft.Graphics.Canvas.Effects;
+using Microsoft.UI;
+using Microsoft.UI.Composition;
+using Microsoft.UI.Xaml;
+using Microsoft.UI.Xaml.Controls;
+using Microsoft.UI.Xaml.Hosting;
+using Microsoft.UI.Xaml.Media;
+using Windows.UI;
+
+namespace Microsoft.CmdPal.UI.Controls;
+
+internal sealed partial class BlurImageControl : Control
+{
+    private const string ImageSourceParameterName = "ImageSource";
+
+    private const string BrightnessEffectName = "Brightness";
+    private const string BrightnessOverlayEffectName = "BrightnessOverlay";
+    private const string BlurEffectName = "Blur";
+    private const string TintBlendEffectName = "TintBlend";
+    private const string TintEffectName = "Tint";
+
+#pragma warning disable CA1507 // Use nameof to express symbol names ... some of these refer to effect properties that are separate from the class properties
+    private static readonly string BrightnessSource1AmountEffectProperty = GetPropertyName(BrightnessEffectName, "Source1Amount");
+    private static readonly string BrightnessSource2AmountEffectProperty = GetPropertyName(BrightnessEffectName, "Source2Amount");
+    private static readonly string BrightnessOverlayColorEffectProperty = GetPropertyName(BrightnessOverlayEffectName, "Color");
+    private static readonly string BlurBlurAmountEffectProperty = GetPropertyName(BlurEffectName, "BlurAmount");
+    private static readonly string TintColorEffectProperty = GetPropertyName(TintEffectName, "Color");
+#pragma warning restore CA1507
+
+    private static readonly string[] AnimatableProperties = [
+        BrightnessSource1AmountEffectProperty,
+        BrightnessSource2AmountEffectProperty,
+        BrightnessOverlayColorEffectProperty,
+        BlurBlurAmountEffectProperty,
+        TintColorEffectProperty
+    ];
+
+    public static readonly DependencyProperty ImageSourceProperty =
+        DependencyProperty.Register(
+            nameof(ImageSource),
+            typeof(ImageSource),
+            typeof(BlurImageControl),
+            new PropertyMetadata(null, OnImageChanged));
+
+    public static readonly DependencyProperty ImageStretchProperty =
+        DependencyProperty.Register(
+            nameof(ImageStretch),
+            typeof(Stretch),
+            typeof(BlurImageControl),
+            new PropertyMetadata(Stretch.UniformToFill, OnImageStretchChanged));
+
+    public static readonly DependencyProperty ImageOpacityProperty =
+        DependencyProperty.Register(
+            nameof(ImageOpacity),
+            typeof(double),
+            typeof(BlurImageControl),
+            new PropertyMetadata(1.0, OnOpacityChanged));
+
+    public static readonly DependencyProperty ImageBrightnessProperty =
+        DependencyProperty.Register(
+            nameof(ImageBrightness),
+            typeof(double),
+            typeof(BlurImageControl),
+            new PropertyMetadata(1.0, OnBrightnessChanged));
+
+    public static readonly DependencyProperty BlurAmountProperty =
+        DependencyProperty.Register(
+            nameof(BlurAmount),
+            typeof(double),
+            typeof(BlurImageControl),
+            new PropertyMetadata(0.0, OnBlurAmountChanged));
+
+    public static readonly DependencyProperty TintColorProperty =
+        DependencyProperty.Register(
+            nameof(TintColor),
+            typeof(Color),
+            typeof(BlurImageControl),
+            new PropertyMetadata(Colors.Transparent, OnVisualPropertyChanged));
+
+    public static readonly DependencyProperty TintIntensityProperty =
+        DependencyProperty.Register(
+            nameof(TintIntensity),
+            typeof(double),
+            typeof(BlurImageControl),
+            new PropertyMetadata(0.0, OnVisualPropertyChanged));
+
+    private Compositor? _compositor;
+    private SpriteVisual? _effectVisual;
+    private CompositionEffectBrush? _effectBrush;
+    private CompositionSurfaceBrush? _imageBrush;
+
+    public BlurImageControl()
+    {
+        this.DefaultStyleKey = typeof(BlurImageControl);
+        this.Loaded += OnLoaded;
+        this.SizeChanged += OnSizeChanged;
+    }
+
+    public ImageSource ImageSource
+    {
+        get => (ImageSource)GetValue(ImageSourceProperty);
+        set => SetValue(ImageSourceProperty, value);
+    }
+
+    public Stretch ImageStretch
+    {
+        get => (Stretch)GetValue(ImageStretchProperty);
+        set => SetValue(ImageStretchProperty, value);
+    }
+
+    public double ImageOpacity
+    {
+        get => (double)GetValue(ImageOpacityProperty);
+        set => SetValue(ImageOpacityProperty, value);
+    }
+
+    public double ImageBrightness
+    {
+        get => (double)GetValue(ImageBrightnessProperty);
+        set => SetValue(ImageBrightnessProperty, Math.Clamp(value, -1, 1));
+    }
+
+    public double BlurAmount
+    {
+        get => (double)GetValue(BlurAmountProperty);
+        set => SetValue(BlurAmountProperty, value);
+    }
+
+    public Color TintColor
+    {
+        get => (Color)GetValue(TintColorProperty);
+        set => SetValue(TintColorProperty, value);
+    }
+
+    public double TintIntensity
+    {
+        get => (double)GetValue(TintIntensityProperty);
+        set => SetValue(TintIntensityProperty, value);
+    }
+
+    private static void OnImageStretchChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
+    {
+        if (d is BlurImageControl control && control._imageBrush != null)
+        {
+            control._imageBrush.Stretch = ConvertStretch((Stretch)e.NewValue);
+        }
+    }
+
+    private static void OnVisualPropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
+    {
+        if (d is BlurImageControl control && control._compositor != null)
+        {
+            control.UpdateEffect();
+        }
+    }
+
+    private static void OnOpacityChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
+    {
+        if (d is BlurImageControl control && control._effectVisual != null)
+        {
+            control._effectVisual.Opacity = (float)(double)e.NewValue;
+        }
+    }
+
+    private static void OnBlurAmountChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
+    {
+        if (d is BlurImageControl control && control._effectBrush != null)
+        {
+            control.UpdateEffect();
+        }
+    }
+
+    private static void OnBrightnessChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
+    {
+        if (d is BlurImageControl control && control._effectBrush != null)
+        {
+            control.UpdateEffect();
+        }
+    }
+
+    private void OnLoaded(object sender, RoutedEventArgs e)
+    {
+        InitializeComposition();
+    }
+
+    private void OnSizeChanged(object sender, SizeChangedEventArgs e)
+    {
+        if (_effectVisual != null)
+        {
+            _effectVisual.Size = new Vector2(
+                (float)Math.Max(1, e.NewSize.Width),
+                (float)Math.Max(1, e.NewSize.Height));
+        }
+    }
+
+    private static void OnImageChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
+    {
+        if (d is not BlurImageControl control)
+        {
+            return;
+        }
+
+        control.EnsureEffect(force: true);
+        control.UpdateEffect();
+    }
+
+    private void InitializeComposition()
+    {
+        var visual = ElementCompositionPreview.GetElementVisual(this);
+        _compositor = visual.Compositor;
+
+        _effectVisual = _compositor.CreateSpriteVisual();
+        _effectVisual.Size = new Vector2(
+            (float)Math.Max(1, ActualWidth),
+            (float)Math.Max(1, ActualHeight));
+        _effectVisual.Opacity = (float)ImageOpacity;
+
+        ElementCompositionPreview.SetElementChildVisual(this, _effectVisual);
+
+        UpdateEffect();
+    }
+
+    private void EnsureEffect(bool force = false)
+    {
+        if (_compositor is null)
+        {
+            return;
+        }
+
+        if (_effectBrush is not null && !force)
+        {
+            return;
+        }
+
+        var imageSource = new CompositionEffectSourceParameter(ImageSourceParameterName);
+
+        // 1) Brightness via ArithmeticCompositeEffect
+        // We blend between the original image and either black or white,
+        // depending on whether we want to darken or brighten. BrightnessEffect isn't supported
+        // in the composition graph.
+        var brightnessEffect = new ArithmeticCompositeEffect
+        {
+            Name = BrightnessEffectName,
+            Source1 = imageSource, // original image
+            Source2 = new ColorSourceEffect
+            {
+                Name = BrightnessOverlayEffectName,
+                Color = Colors.Black, // we'll swap black/white via properties
+            },
+
+            MultiplyAmount = 0.0f,
+            Source1Amount = 1.0f, // original
+            Source2Amount = 0.0f, // overlay
+            Offset = 0.0f,
+        };
+
+        // 2) Blur
+        var blurEffect = new GaussianBlurEffect
+        {
+            Name = BlurEffectName,
+            BlurAmount = 0.0f,
+            BorderMode = EffectBorderMode.Hard,
+            Optimization = EffectOptimization.Balanced,
+            Source = brightnessEffect,
+        };
+
+        // 3) Tint (always in the chain; intensity via alpha)
+        var tintEffect = new BlendEffect
+        {
+            Name = TintBlendEffectName,
+            Background = blurEffect,
+            Foreground = new ColorSourceEffect
+            {
+                Name = TintEffectName,
+                Color = Colors.Transparent,
+            },
+            Mode = BlendEffectMode.Multiply,
+        };
+
+        var effectFactory = _compositor.CreateEffectFactory(tintEffect, AnimatableProperties);
+
+        _effectBrush?.Dispose();
+        _effectBrush = effectFactory.CreateBrush();
+
+        // Set initial source
+        if (ImageSource is not null)
+        {
+            _imageBrush ??= _compositor.CreateSurfaceBrush();
+            LoadImageAsync(ImageSource);
+            _effectBrush.SetSourceParameter(ImageSourceParameterName, _imageBrush);
+        }
+        else
+        {
+            _effectBrush.SetSourceParameter(ImageSourceParameterName, _compositor.CreateBackdropBrush());
+        }
+
+        if (_effectVisual is not null)
+        {
+            _effectVisual.Brush = _effectBrush;
+        }
+    }
+
+    private void UpdateEffect()
+    {
+        if (_compositor is null)
+        {
+            return;
+        }
+
+        EnsureEffect();
+        if (_effectBrush is null)
+        {
+            return;
+        }
+
+        var props = _effectBrush.Properties;
+
+        // Brightness
+        var b = (float)Math.Clamp(ImageBrightness, -1.0, 1.0);
+
+        float source1Amount;
+        float source2Amount;
+        Color overlayColor;
+
+        if (b >= 0)
+        {
+            // Brighten: blend towards white
+            overlayColor = Colors.White;
+            source1Amount = 1.0f - b; // original image contribution
+            source2Amount = b;        // white overlay contribution
+        }
+        else
+        {
+            // Darken: blend towards black
+            overlayColor = Colors.Black;
+            var t = -b;               // 0..1
+            source1Amount = 1.0f - t; // original image
+            source2Amount = t;        // black overlay
+        }
+
+        props.InsertScalar(BrightnessSource1AmountEffectProperty, source1Amount);
+        props.InsertScalar(BrightnessSource2AmountEffectProperty, source2Amount);
+        props.InsertColor(BrightnessOverlayColorEffectProperty, overlayColor);
+
+        // Blur
+        props.InsertScalar(BlurBlurAmountEffectProperty, (float)BlurAmount);
+
+        // Tint
+        var tintColor = TintColor;
+        var clampedIntensity = (float)Math.Clamp(TintIntensity, 0.0, 1.0);
+
+        var adjustedColor = Color.FromArgb(
+            (byte)(clampedIntensity * 255),
+            tintColor.R,
+            tintColor.G,
+            tintColor.B);
+
+        props.InsertColor(TintColorEffectProperty, adjustedColor);
+    }
+
+    private void LoadImageAsync(ImageSource imageSource)
+    {
+        try
+        {
+            if (imageSource is Microsoft.UI.Xaml.Media.Imaging.BitmapImage bitmapImage)
+            {
+                _imageBrush ??= _compositor?.CreateSurfaceBrush();
+                if (_imageBrush is null)
+                {
+                    return;
+                }
+
+                var loadedSurface = LoadedImageSurface.StartLoadFromUri(bitmapImage.UriSource);
+                loadedSurface.LoadCompleted += (_, _) =>
+                {
+                    if (_imageBrush is not null)
+                    {
+                        _imageBrush.Surface = loadedSurface;
+                        _imageBrush.Stretch = ConvertStretch(ImageStretch);
+                        _imageBrush.BitmapInterpolationMode = CompositionBitmapInterpolationMode.Linear;
+                    }
+                };
+
+                _effectBrush?.SetSourceParameter(ImageSourceParameterName, _imageBrush);
+            }
+        }
+        catch (Exception ex)
+        {
+            Logger.LogError("Failed to load image for BlurImageControl: {0}", ex);
+        }
+    }
+
+    private static CompositionStretch ConvertStretch(Stretch stretch)
+    {
+        return stretch switch
+        {
+            Stretch.None => CompositionStretch.None,
+            Stretch.Fill => CompositionStretch.Fill,
+            Stretch.Uniform => CompositionStretch.Uniform,
+            Stretch.UniformToFill => CompositionStretch.UniformToFill,
+            _ => CompositionStretch.UniformToFill,
+        };
+    }
+
+    private static string GetPropertyName(string effectName, string propertyName) => $"{effectName}.{propertyName}";
+}

src/modules/cmdpal/Microsoft.CmdPal.UI/Controls/ColorPalette.xaml

@@ -0,0 +1,216 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<UserControl
+    x:Class="Microsoft.CmdPal.UI.Controls.ColorPalette"
+    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+    xmlns:controls="using:CommunityToolkit.WinUI.Controls"
+    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
+    xmlns:local="using:Microsoft.CmdPal.UI.Controls"
+    xmlns:localConverters="using:Microsoft.CmdPal.UI.Converters"
+    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
+    xmlns:toolkitConverters="using:CommunityToolkit.WinUI.Converters"
+    xmlns:ui="using:CommunityToolkit.WinUI"
+    mc:Ignorable="d">
+    <UserControl.Resources>
+
+        <toolkitConverters:ColorToDisplayNameConverter x:Key="ColorToDisplayNameConverter" />
+        <localConverters:ContrastBrushConverter x:Key="ContrastBrushConverter" />
+
+        <Style x:Key="PaletteGridViewItemStyle" TargetType="GridViewItem">
+            <Setter Property="FontFamily" Value="{ThemeResource ContentControlThemeFontFamily}" />
+            <Setter Property="FontSize" Value="{ThemeResource ControlContentThemeFontSize}" />
+            <Setter Property="Background" Value="Transparent" />
+            <Setter Property="Foreground" Value="{ThemeResource SystemControlForegroundBaseHighBrush}" />
+            <Setter Property="TabNavigation" Value="Local" />
+            <Setter Property="IsHoldingEnabled" Value="True" />
+            <Setter Property="HorizontalContentAlignment" Value="Stretch" />
+            <Setter Property="VerticalContentAlignment" Value="Stretch" />
+            <Setter Property="Margin" Value="0" />
+            <Setter Property="Padding" Value="0" />
+            <Setter Property="MinWidth" Value="32" />
+            <Setter Property="MinHeight" Value="32" />
+            <Setter Property="AllowDrop" Value="False" />
+            <Setter Property="UseSystemFocusVisuals" Value="{StaticResource UseSystemFocusVisuals}" />
+            <Setter Property="FocusVisualMargin" Value="-2" />
+            <Setter Property="Template">
+                <Setter.Value>
+                    <ControlTemplate TargetType="GridViewItem">
+                        <Grid
+                            x:Name="ContentBorder"
+                            Background="{TemplateBinding Background}"
+                            BorderBrush="{TemplateBinding BorderBrush}"
+                            BorderThickness="{TemplateBinding BorderThickness}"
+                            Control.IsTemplateFocusTarget="True"
+                            CornerRadius="{TemplateBinding CornerRadius}"
+                            FocusVisualMargin="{TemplateBinding FocusVisualMargin}"
+                            RenderTransformOrigin="0.5,0.5">
+                            <Grid.RenderTransform>
+                                <ScaleTransform x:Name="ContentBorderScale" />
+                            </Grid.RenderTransform>
+                            <ContentPresenter
+                                x:Name="ContentPresenter"
+                                Margin="{TemplateBinding Padding}"
+                                HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}"
+                                VerticalAlignment="{TemplateBinding VerticalContentAlignment}"
+                                ContentTransitions="{TemplateBinding ContentTransitions}" />
+                            <!--
+                                The 'Xg' text simulates the amount of space one line of text will occupy.
+                                In the DataPlaceholder state, the Content is not loaded yet so we
+                                approximate the size of the item using placeholder text.
+                            -->
+                            <TextBlock
+                                x:Name="PlaceholderTextBlock"
+                                Margin="{TemplateBinding Padding}"
+                                AutomationProperties.AccessibilityView="Raw"
+                                Foreground="{x:Null}"
+                                IsHitTestVisible="False"
+                                Text="Xg"
+                                Visibility="Collapsed" />
+                            <Rectangle
+                                x:Name="PlaceholderRect"
+                                Fill="{ThemeResource ListViewItemPlaceholderBackground}"
+                                Visibility="Collapsed" />
+                            <Rectangle
+                                x:Name="BorderRectangle"
+                                IsHitTestVisible="False"
+                                Opacity="0"
+                                RadiusX="6"
+                                RadiusY="6"
+                                Stroke="{ThemeResource SystemControlHighlightListAccentLowBrush}"
+                                StrokeThickness="2" />
+                            <Border
+                                x:Name="MultiSelectSquare"
+                                Width="20"
+                                Height="20"
+                                Margin="0,2,2,0"
+                                HorizontalAlignment="Right"
+                                VerticalAlignment="Top"
+                                Background="{ThemeResource SystemControlBackgroundChromeMediumBrush}"
+                                CornerRadius="6"
+                                Visibility="Collapsed">
+                                <FontIcon
+                                    x:Name="MultiSelectCheck"
+                                    FontFamily="{ThemeResource SymbolThemeFontFamily}"
+                                    FontSize="16"
+                                    Foreground="{ThemeResource SystemControlForegroundBaseMediumHighBrush}"
+                                    Glyph="&#xE73E;"
+                                    Opacity="0" />
+                            </Border>
+                            <Border
+                                x:Name="MultiArrangeOverlayTextBorder"
+                                Height="20"
+                                MinWidth="20"
+                                HorizontalAlignment="Center"
+                                VerticalAlignment="Center"
+                                Background="{ThemeResource SystemControlBackgroundAccentBrush}"
+                                BorderBrush="{ThemeResource SystemControlBackgroundChromeWhiteBrush}"
+                                BorderThickness="2"
+                                CornerRadius="6"
+                                IsHitTestVisible="False"
+                                Opacity="0">
+                                <TextBlock
+                                    x:Name="MultiArrangeOverlayText"
+                                    HorizontalAlignment="Center"
+                                    VerticalAlignment="Center"
+                                    AutomationProperties.AccessibilityView="Raw"
+                                    IsHitTestVisible="False"
+                                    Opacity="0"
+                                    Style="{ThemeResource CaptionTextBlockStyle}"
+                                    Text="{Binding RelativeSource={RelativeSource TemplatedParent}, Path=TemplateSettings.DragItemsCount}" />
+                            </Border>
+                            <VisualStateManager.VisualStateGroups>
+                                <VisualStateGroup x:Name="FocusStates">
+                                    <VisualState x:Name="Focused">
+
+                                        <Storyboard>
+                                            <ObjectAnimationUsingKeyFrames Storyboard.TargetName="BorderRectangle" Storyboard.TargetProperty="Visibility">
+                                                <DiscreteObjectKeyFrame KeyTime="0" Value="Collapsed" />
+                                            </ObjectAnimationUsingKeyFrames>
+                                        </Storyboard>
+                                    </VisualState>
+                                    <VisualState x:Name="Unfocused" />
+
+                                </VisualStateGroup>
+                                <VisualStateGroup x:Name="CommonStates">
+                                    <VisualState x:Name="Normal">
+
+                                        <Storyboard>
+                                            <PointerUpThemeAnimation Storyboard.TargetName="ContentPresenter" />
+                                        </Storyboard>
+                                    </VisualState>
+
+                                    <VisualState x:Name="PointerOver">
+
+                                        <Storyboard>
+                                            <DoubleAnimation
+                                                Storyboard.TargetName="BorderRectangle"
+                                                Storyboard.TargetProperty="Opacity"
+                                                To="1"
+                                                Duration="0" />
+                                            <ObjectAnimationUsingKeyFrames Storyboard.TargetName="BorderRectangle" Storyboard.TargetProperty="Stroke">
+                                                <DiscreteObjectKeyFrame KeyTime="0" Value="{Binding Converter={StaticResource ContrastBrushConverter}, ConverterParameter={ThemeResource TextControlForeground}}" />
+                                            </ObjectAnimationUsingKeyFrames>
+                                            <ObjectAnimationUsingKeyFrames Storyboard.TargetName="ContentPresenter" Storyboard.TargetProperty="Foreground">
+                                                <DiscreteObjectKeyFrame KeyTime="0" Value="{Binding Converter={StaticResource ContrastBrushConverter}, ConverterParameter={ThemeResource TextControlForeground}}" />
+                                            </ObjectAnimationUsingKeyFrames>
+                                            <ObjectAnimationUsingKeyFrames Storyboard.TargetName="ContentBorder" Storyboard.TargetProperty="FocusVisualSecondaryBrush">
+                                                <DiscreteObjectKeyFrame KeyTime="0" Value="{Binding Converter={StaticResource ContrastBrushConverter}, ConverterParameter={ThemeResource TextControlForeground}}" />
+                                            </ObjectAnimationUsingKeyFrames>
+                                            <ObjectAnimationUsingKeyFrames Storyboard.TargetName="ContentBorder" Storyboard.TargetProperty="FocusVisualSecondaryThickness">
+                                                <DiscreteObjectKeyFrame KeyTime="0" Value="2" />
+                                            </ObjectAnimationUsingKeyFrames>
+                                            <PointerUpThemeAnimation Storyboard.TargetName="ContentPresenter" />
+
+                                            <DoubleAnimation
+                                                Storyboard.TargetName="MultiSelectCheck"
+                                                Storyboard.TargetProperty="Opacity"
+                                                To="1"
+                                                Duration="0" />
+                                            <ObjectAnimationUsingKeyFrames Storyboard.TargetName="MultiSelectSquare" Storyboard.TargetProperty="Background">
+                                                <DiscreteObjectKeyFrame KeyTime="0" Value="{Binding Converter={StaticResource ContrastBrushConverter}, ConverterParameter={ThemeResource TextControlForeground}}" />
+                                            </ObjectAnimationUsingKeyFrames>
+                                        </Storyboard>
+                                    </VisualState>
+
+                                </VisualStateGroup>
+                            </VisualStateManager.VisualStateGroups>
+                        </Grid>
+
+                    </ControlTemplate>
+                </Setter.Value>
+            </Setter>
+        </Style>
+    </UserControl.Resources>
+
+    <Grid HorizontalAlignment="Stretch">
+        <GridView
+            Margin="0"
+            Padding="0"
+            IsItemClickEnabled="True"
+            ItemClick="ListViewBase_OnItemClick"
+            ItemContainerStyle="{StaticResource PaletteGridViewItemStyle}"
+            ItemsSource="{x:Bind PaletteColors}"
+            SelectionMode="None">
+            <GridView.ItemsPanel>
+                <ItemsPanelTemplate>
+                    <controls:UniformGrid ui:FrameworkElementExtensions.AncestorType="local:ColorPalette" Columns="{Binding (ui:FrameworkElementExtensions.Ancestor).CustomPaletteColumnCount, RelativeSource={RelativeSource Self}}" />
+                </ItemsPanelTemplate>
+            </GridView.ItemsPanel>
+            <GridView.ItemTemplate>
+                <DataTemplate x:DataType="Color">
+                    <Border
+                        Margin="2"
+                        HorizontalAlignment="Stretch"
+                        VerticalAlignment="Stretch"
+                        AutomationProperties.Name="{Binding Converter={StaticResource ColorToDisplayNameConverter}}"
+                        CornerRadius="4"
+                        ToolTipService.ToolTip="{Binding Converter={StaticResource ColorToDisplayNameConverter}}">
+                        <Border.Background>
+                            <SolidColorBrush Color="{Binding}" />
+                        </Border.Background>
+                    </Border>
+                </DataTemplate>
+            </GridView.ItemTemplate>
+        </GridView>
+    </Grid>
+</UserControl>

src/modules/cmdpal/Microsoft.CmdPal.UI/Controls/ColorPalette.xaml.cs

@@ -0,0 +1,71 @@
+// Copyright (c) Microsoft Corporation
+// The Microsoft Corporation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System.Collections.ObjectModel;
+using Microsoft.UI.Xaml;
+using Microsoft.UI.Xaml.Controls;
+using Windows.UI;
+
+namespace Microsoft.CmdPal.UI.Controls;
+
+public sealed partial class ColorPalette : UserControl
+{
+    public static readonly DependencyProperty PaletteColorsProperty = DependencyProperty.Register(nameof(PaletteColors), typeof(ObservableCollection<Color>), typeof(ColorPalette), null!)!;
+
+    public static readonly DependencyProperty CustomPaletteColumnCountProperty = DependencyProperty.Register(nameof(CustomPaletteColumnCount), typeof(int), typeof(ColorPalette), new PropertyMetadata(10))!;
+
+    public static readonly DependencyProperty SelectedColorProperty = DependencyProperty.Register(nameof(SelectedColor), typeof(Color), typeof(ColorPalette), new PropertyMetadata(null!))!;
+
+    public event EventHandler<Color?>? SelectedColorChanged;
+
+    private Color? _selectedColor;
+
+    public Color? SelectedColor
+    {
+        get => _selectedColor;
+
+        set
+        {
+            if (_selectedColor != value)
+            {
+                _selectedColor = value;
+                if (value is not null)
+                {
+                    SetValue(SelectedColorProperty, value);
+                }
+                else
+                {
+                    ClearValue(SelectedColorProperty);
+                }
+            }
+        }
+    }
+
+    public ObservableCollection<Color> PaletteColors
+    {
+        get => (ObservableCollection<Color>)GetValue(PaletteColorsProperty)!;
+        set => SetValue(PaletteColorsProperty, value);
+    }
+
+    public int CustomPaletteColumnCount
+    {
+        get => (int)GetValue(CustomPaletteColumnCountProperty);
+        set => SetValue(CustomPaletteColumnCountProperty, value);
+    }
+
+    public ColorPalette()
+    {
+        PaletteColors = [];
+        InitializeComponent();
+    }
+
+    private void ListViewBase_OnItemClick(object sender, ItemClickEventArgs e)
+    {
+        if (e.ClickedItem is Color color)
+        {
+            SelectedColor = color;
+            SelectedColorChanged?.Invoke(this, color);
+        }
+    }
+}

src/modules/cmdpal/Microsoft.CmdPal.UI/Controls/ColorPickerButton.xaml

@@ -0,0 +1,90 @@
+<UserControl
+    x:Class="Microsoft.CmdPal.UI.Controls.ColorPickerButton"
+    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+    xmlns:controls="using:Microsoft.CmdPal.UI.Controls"
+    xmlns:converters="using:CommunityToolkit.WinUI.Converters"
+    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
+    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
+    d:DesignHeight="300"
+    d:DesignWidth="400"
+    mc:Ignorable="d">
+    <UserControl.Resources>
+        <converters:BoolToVisibilityConverter x:Key="BoolToVisibilityConverter" />
+        <converters:BoolToVisibilityConverter
+            x:Key="BoolToVisibilityInvertedConverter"
+            FalseValue="Visible"
+            TrueValue="Collapsed" />
+    </UserControl.Resources>
+
+    <StackPanel Orientation="Horizontal" Spacing="8">
+        <DropDownButton Padding="{x:Bind ToDropDownPadding(HasSelectedColor), Mode=OneWay}">
+            <Grid>
+                <TextBlock x:Uid="OptionalColorPickerButton_UnsetTextBlock" Visibility="{x:Bind HasSelectedColor, Mode=OneWay, Converter={StaticResource BoolToVisibilityInvertedConverter}}" />
+                <Border
+                    x:Name="ColorPreviewBorder"
+                    Width="48"
+                    Height="24"
+                    BorderBrush="{ThemeResource CardStrokeColorDefaultBrush}"
+                    BorderThickness="1"
+                    CornerRadius="{ThemeResource ControlCornerRadius}"
+                    Visibility="{x:Bind HasSelectedColor, Mode=OneWay, Converter={StaticResource BoolToVisibilityConverter}}">
+                    <Border.Background>
+                        <SolidColorBrush Color="{x:Bind SelectedColor, Mode=OneWay}" />
+                    </Border.Background>
+                </Border>
+            </Grid>
+            <DropDownButton.Flyout>
+                <Flyout
+                    x:Name="ColorPickerFlyout"
+                    Opened="FlyoutBase_OnOpened"
+                    Placement="Bottom"
+                    ShouldConstrainToRootBounds="False">
+                    <Flyout.FlyoutPresenterStyle>
+                        <Style BasedOn="{StaticResource DefaultFlyoutPresenterStyle}" TargetType="FlyoutPresenter">
+                            <Setter Property="MinWidth" Value="660" />
+                        </Style>
+                    </Flyout.FlyoutPresenterStyle>
+                    <StackPanel
+                        x:Name="FlyoutRoot"
+                        Orientation="Horizontal"
+                        SizeChanged="FlyoutRoot_OnSizeChanged"
+                        Spacing="20">
+                        <!--  Left column: Preset colors and reset button  -->
+                        <StackPanel Margin="2">
+                            <TextBlock
+                                x:Uid="OptionalColorPickerButton_WindowsColorsSectionHeading"
+                                Margin="0,0,0,12"
+                                Style="{StaticResource BodyTextBlockStyle}" />
+
+                            <controls:ColorPalette
+                                HorizontalAlignment="Left"
+                                VerticalAlignment="Top"
+                                CustomPaletteColumnCount="9"
+                                PaletteColors="{x:Bind PaletteColors}"
+                                SelectedColorChanged="ColorPalette_OnSelectedColorChanged" />
+                        </StackPanel>
+
+                        <!--  Right column: Spectrum  -->
+                        <StackPanel>
+                            <TextBlock
+                                x:Uid="OptionalColorPickerButton_CustomColorsSectionHeading"
+                                Margin="0,0,0,12"
+                                Style="{StaticResource BodyTextBlockStyle}" />
+
+                            <ColorPicker
+                                IsAlphaEnabled="{x:Bind IsAlphaEnabled, Mode=OneWay}"
+                                IsAlphaSliderVisible="{x:Bind IsAlphaEnabled, Mode=OneWay}"
+                                IsAlphaTextInputVisible="{x:Bind IsAlphaEnabled, Mode=OneWay}"
+                                IsColorChannelTextInputVisible="True"
+                                IsColorSliderVisible="True"
+                                IsHexInputVisible="True"
+                                IsMoreButtonVisible="True"
+                                Color="{x:Bind SelectedColor, Mode=TwoWay}" />
+                        </StackPanel>
+                    </StackPanel>
+                </Flyout>
+            </DropDownButton.Flyout>
+        </DropDownButton>
+    </StackPanel>
+</UserControl>

src/modules/cmdpal/Microsoft.CmdPal.UI/Controls/ColorPickerButton.xaml.cs

@@ -0,0 +1,146 @@
+// Copyright (c) Microsoft Corporation
+// The Microsoft Corporation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System.Collections.ObjectModel;
+using ManagedCommon;
+using Microsoft.UI;
+using Microsoft.UI.Xaml;
+using Microsoft.UI.Xaml.Controls;
+using Windows.UI;
+
+namespace Microsoft.CmdPal.UI.Controls;
+
+public sealed partial class ColorPickerButton : UserControl
+{
+    public static readonly DependencyProperty PaletteColorsProperty = DependencyProperty.Register(nameof(PaletteColors), typeof(ObservableCollection<Color>), typeof(ColorPickerButton), new PropertyMetadata(new ObservableCollection<Color>()))!;
+
+    public static readonly DependencyProperty SelectedColorProperty = DependencyProperty.Register(nameof(SelectedColor), typeof(Color), typeof(ColorPickerButton), new PropertyMetadata(Colors.Black))!;
+
+    public static readonly DependencyProperty IsAlphaEnabledProperty = DependencyProperty.Register(nameof(IsAlphaEnabled), typeof(bool), typeof(ColorPickerButton), new PropertyMetadata(defaultValue: false))!;
+
+    public static readonly DependencyProperty IsValueEditorEnabledProperty = DependencyProperty.Register(nameof(IsValueEditorEnabled), typeof(bool), typeof(ColorPickerButton), new PropertyMetadata(false))!;
+
+    public static readonly DependencyProperty HasSelectedColorProperty = DependencyProperty.Register(nameof(HasSelectedColor), typeof(bool), typeof(ColorPickerButton), new PropertyMetadata(false))!;
+
+    private Color _selectedColor;
+
+    public Color SelectedColor
+    {
+        get
+        {
+            return _selectedColor;
+        }
+
+        set
+        {
+            if (_selectedColor != value)
+            {
+                _selectedColor = value;
+                SetValue(SelectedColorProperty, value);
+                HasSelectedColor = true;
+            }
+        }
+    }
+
+    public bool HasSelectedColor
+    {
+        get { return (bool)GetValue(HasSelectedColorProperty); }
+        set { SetValue(HasSelectedColorProperty, value); }
+    }
+
+    public bool IsAlphaEnabled
+    {
+        get => (bool)GetValue(IsAlphaEnabledProperty);
+        set => SetValue(IsAlphaEnabledProperty, value);
+    }
+
+    public bool IsValueEditorEnabled
+    {
+        get { return (bool)GetValue(IsValueEditorEnabledProperty); }
+        set { SetValue(IsValueEditorEnabledProperty, value); }
+    }
+
+    public ObservableCollection<Color> PaletteColors
+    {
+        get { return (ObservableCollection<Color>)GetValue(PaletteColorsProperty); }
+        set { SetValue(PaletteColorsProperty, value); }
+    }
+
+    public ColorPickerButton()
+    {
+        this.InitializeComponent();
+
+        IsEnabledChanged -= ColorPickerButton_IsEnabledChanged;
+        SetEnabledState();
+        IsEnabledChanged += ColorPickerButton_IsEnabledChanged;
+    }
+
+    private void ColorPickerButton_IsEnabledChanged(object sender, DependencyPropertyChangedEventArgs e)
+    {
+        SetEnabledState();
+    }
+
+    private void SetEnabledState()
+    {
+        if (this.IsEnabled)
+        {
+            ColorPreviewBorder.Opacity = 1;
+        }
+        else
+        {
+            ColorPreviewBorder.Opacity = 0.2;
+        }
+    }
+
+    private void ColorPalette_OnSelectedColorChanged(object? sender, Color? e)
+    {
+        if (e.HasValue)
+        {
+            HasSelectedColor = true;
+            SelectedColor = e.Value;
+        }
+    }
+
+    private void FlyoutBase_OnOpened(object? sender, object e)
+    {
+        if (sender is not Flyout flyout || (flyout.Content as FrameworkElement)?.Parent is not FlyoutPresenter flyoutPresenter)
+        {
+            return;
+        }
+
+        FlyoutRoot!.UpdateLayout();
+        flyoutPresenter.UpdateLayout();
+
+        // Logger.LogInfo($"FlyoutBase_OnOpened: {flyoutPresenter}, {FlyoutRoot!.ActualWidth}");
+        flyoutPresenter.MaxWidth = FlyoutRoot!.ActualWidth;
+        flyoutPresenter.MinWidth = 660;
+        flyoutPresenter.Width = FlyoutRoot!.ActualWidth;
+    }
+
+    private void FlyoutRoot_OnSizeChanged(object sender, SizeChangedEventArgs e)
+    {
+        if ((ColorPickerFlyout!.Content as FrameworkElement)?.Parent is not FlyoutPresenter flyoutPresenter)
+        {
+            return;
+        }
+
+        FlyoutRoot!.UpdateLayout();
+        flyoutPresenter.UpdateLayout();
+
+        flyoutPresenter.MaxWidth = FlyoutRoot!.ActualWidth;
+        flyoutPresenter.MinWidth = 660;
+        flyoutPresenter.Width = FlyoutRoot!.ActualWidth;
+    }
+
+    private Thickness ToDropDownPadding(bool hasColor)
+    {
+        return hasColor ? new Thickness(3, 3, 8, 3) : new Thickness(8, 4, 8, 4);
+    }
+
+    private void ResetButton_Click(object sender, RoutedEventArgs e)
+    {
+        HasSelectedColor = false;
+        ColorPickerFlyout?.Hide();
+    }
+}

src/modules/cmdpal/Microsoft.CmdPal.UI/Controls/CommandPalettePreview.xaml

@@ -0,0 +1,75 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<UserControl
+    x:Class="Microsoft.CmdPal.UI.Controls.CommandPalettePreview"
+    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
+    xmlns:h="using:Microsoft.CmdPal.UI.Helpers"
+    xmlns:local="using:Microsoft.CmdPal.UI.Controls"
+    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
+    mc:Ignorable="d">
+    <Border
+        Width="200"
+        Height="120"
+        BorderBrush="{ThemeResource SurfaceStrokeColorDefaultBrush}"
+        BorderThickness="1"
+        CornerRadius="8"
+        Translation="0,0,8">
+        <Grid>
+            <Border
+                HorizontalAlignment="Stretch"
+                VerticalAlignment="Stretch"
+                BorderBrush="{ThemeResource SurfaceStrokeColorDefaultBrush}"
+                BorderThickness="1"
+                Visibility="{x:Bind h:BindTransformers.NegateVisibility(ShowBackgroundImage), Mode=OneWay}">
+                <Border.Background>
+                    <AcrylicBrush
+                        FallbackColor="{x:Bind PreviewBackgroundColor, Mode=OneWay}"
+                        TintColor="{x:Bind PreviewBackgroundColor, Mode=OneWay}"
+                        TintOpacity="{x:Bind PreviewBackgroundOpacity, Mode=OneWay}" />
+                </Border.Background>
+            </Border>
+            <local:BlurImageControl
+                HorizontalAlignment="Stretch"
+                VerticalAlignment="Stretch"
+                BlurAmount="{x:Bind PreviewBackgroundImageBlurAmount, Mode=OneWay}"
+                ImageBrightness="{x:Bind PreviewBackgroundImageBrightness, Mode=OneWay}"
+                ImageSource="{x:Bind PreviewBackgroundImageSource, Mode=OneWay}"
+                ImageStretch="{x:Bind ToStretch(PreviewBackgroundImageFit), Mode=OneWay}"
+                IsHitTestVisible="False"
+                TintColor="{x:Bind PreviewBackgroundImageTint, Mode=OneWay}"
+                TintIntensity="{x:Bind ToTintIntensity(PreviewBackgroundImageTintIntensity), Mode=OneWay}"
+                Visibility="{x:Bind ShowBackgroundImage, Mode=OneWay}" />
+
+            <Grid>
+                <Grid.RowDefinitions>
+                    <RowDefinition Height="100" />
+                    <RowDefinition Height="20" />
+                </Grid.RowDefinitions>
+
+                <Border
+                    x:Name="ContentPreview"
+                    Grid.Row="0"
+                    Background="{ThemeResource LayerOnAcrylicPrimaryBackgroundBrush}">
+                    <Grid>
+                        <Grid.RowDefinitions>
+                            <RowDefinition Height="20" />
+                            <RowDefinition Height="*" />
+                        </Grid.RowDefinitions>
+
+                        <Border BorderBrush="{ThemeResource CmdPal.TopBarBorderBrush}" BorderThickness="0,0,0,1" />
+                    </Grid>
+
+                </Border>
+
+                <Border
+                    x:Name="CommandBarPreview"
+                    Grid.Row="1"
+                    Background="{ThemeResource LayerOnAcrylicSecondaryBackgroundBrush}"
+                    BorderBrush="{ThemeResource CmdPal.CommandBarBorderBrush}"
+                    BorderThickness="0,1,0,0" />
+            </Grid>
+
+        </Grid>
+    </Border>
+</UserControl>

src/modules/cmdpal/Microsoft.CmdPal.UI/Controls/CommandPalettePreview.xaml.cs

@@ -0,0 +1,123 @@
+// Copyright (c) Microsoft Corporation
+// The Microsoft Corporation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using Microsoft.CmdPal.UI.ViewModels;
+using Microsoft.UI.Xaml;
+using Microsoft.UI.Xaml.Controls;
+using Microsoft.UI.Xaml.Media;
+using Windows.UI;
+
+namespace Microsoft.CmdPal.UI.Controls;
+
+public sealed partial class CommandPalettePreview : UserControl
+{
+    public static readonly DependencyProperty PreviewBackgroundOpacityProperty = DependencyProperty.Register(nameof(PreviewBackgroundOpacity), typeof(double), typeof(CommandPalettePreview), new PropertyMetadata(0d));
+
+    public static readonly DependencyProperty PreviewBackgroundColorProperty = DependencyProperty.Register(nameof(PreviewBackgroundColor), typeof(Color), typeof(CommandPalettePreview), new PropertyMetadata(default(Color)));
+
+    public static readonly DependencyProperty PreviewBackgroundImageSourceProperty = DependencyProperty.Register(nameof(PreviewBackgroundImageSource), typeof(ImageSource), typeof(CommandPalettePreview), new PropertyMetadata(null, PropertyChangedCallback));
+
+    public static readonly DependencyProperty PreviewBackgroundImageOpacityProperty = DependencyProperty.Register(nameof(PreviewBackgroundImageOpacity), typeof(int), typeof(CommandPalettePreview), new PropertyMetadata(0));
+
+    public static readonly DependencyProperty PreviewBackgroundImageFitProperty = DependencyProperty.Register(nameof(PreviewBackgroundImageFit), typeof(BackgroundImageFit), typeof(CommandPalettePreview), new PropertyMetadata(default(BackgroundImageFit)));
+
+    public static readonly DependencyProperty PreviewBackgroundImageBrightnessProperty = DependencyProperty.Register(nameof(PreviewBackgroundImageBrightness), typeof(double), typeof(CommandPalettePreview), new PropertyMetadata(0d));
+
+    public static readonly DependencyProperty PreviewBackgroundImageBlurAmountProperty = DependencyProperty.Register(nameof(PreviewBackgroundImageBlurAmount), typeof(double), typeof(CommandPalettePreview), new PropertyMetadata(0d));
+
+    public static readonly DependencyProperty PreviewBackgroundImageTintProperty = DependencyProperty.Register(nameof(PreviewBackgroundImageTint), typeof(Color), typeof(CommandPalettePreview), new PropertyMetadata(default(Color)));
+
+    public static readonly DependencyProperty PreviewBackgroundImageTintIntensityProperty = DependencyProperty.Register(nameof(PreviewBackgroundImageTintIntensity), typeof(int), typeof(CommandPalettePreview), new PropertyMetadata(0));
+
+    public static readonly DependencyProperty ShowBackgroundImageProperty = DependencyProperty.Register(nameof(ShowBackgroundImage), typeof(Visibility), typeof(CommandPalettePreview), new PropertyMetadata(Visibility.Collapsed));
+
+    public BackgroundImageFit PreviewBackgroundImageFit
+    {
+        get { return (BackgroundImageFit)GetValue(PreviewBackgroundImageFitProperty); }
+        set { SetValue(PreviewBackgroundImageFitProperty, value); }
+    }
+
+    public double PreviewBackgroundOpacity
+    {
+        get { return (double)GetValue(PreviewBackgroundOpacityProperty); }
+        set { SetValue(PreviewBackgroundOpacityProperty, value); }
+    }
+
+    public Color PreviewBackgroundColor
+    {
+        get { return (Color)GetValue(PreviewBackgroundColorProperty); }
+        set { SetValue(PreviewBackgroundColorProperty, value); }
+    }
+
+    public ImageSource PreviewBackgroundImageSource
+    {
+        get { return (ImageSource)GetValue(PreviewBackgroundImageSourceProperty); }
+        set { SetValue(PreviewBackgroundImageSourceProperty, value); }
+    }
+
+    public int PreviewBackgroundImageOpacity
+    {
+        get { return (int)GetValue(PreviewBackgroundImageOpacityProperty); }
+        set { SetValue(PreviewBackgroundImageOpacityProperty, value); }
+    }
+
+    public double PreviewBackgroundImageBrightness
+    {
+        get => (double)GetValue(PreviewBackgroundImageBrightnessProperty);
+        set => SetValue(PreviewBackgroundImageBrightnessProperty, value);
+    }
+
+    public double PreviewBackgroundImageBlurAmount
+    {
+        get => (double)GetValue(PreviewBackgroundImageBlurAmountProperty);
+        set => SetValue(PreviewBackgroundImageBlurAmountProperty, value);
+    }
+
+    public Color PreviewBackgroundImageTint
+    {
+        get => (Color)GetValue(PreviewBackgroundImageTintProperty);
+        set => SetValue(PreviewBackgroundImageTintProperty, value);
+    }
+
+    public int PreviewBackgroundImageTintIntensity
+    {
+        get => (int)GetValue(PreviewBackgroundImageTintIntensityProperty);
+        set => SetValue(PreviewBackgroundImageTintIntensityProperty, value);
+    }
+
+    public Visibility ShowBackgroundImage
+    {
+        get => (Visibility)GetValue(ShowBackgroundImageProperty);
+        set => SetValue(ShowBackgroundImageProperty, value);
+    }
+
+    public CommandPalettePreview()
+    {
+        InitializeComponent();
+    }
+
+    private static void PropertyChangedCallback(DependencyObject d, DependencyPropertyChangedEventArgs e)
+    {
+        if (d is not CommandPalettePreview preview)
+        {
+            return;
+        }
+
+        preview.ShowBackgroundImage = e.NewValue is ImageSource ? Visibility.Visible : Visibility.Collapsed;
+    }
+
+    private double ToOpacity(int value) => value / 100.0;
+
+    private double ToTintIntensity(int value) => value / 100.0;
+
+    private Stretch ToStretch(BackgroundImageFit fit)
+    {
+        return fit switch
+        {
+            BackgroundImageFit.Fill => Stretch.Fill,
+            BackgroundImageFit.UniformToFill => Stretch.UniformToFill,
+            _ => Stretch.None,
+        };
+    }
+}

src/modules/cmdpal/Microsoft.CmdPal.UI/Controls/FallbackRanker.xaml.cs

@@ -3,6 +3,7 @@
 // See the LICENSE file in the project root for more information.
 
 using Microsoft.CmdPal.UI.ViewModels;
+using Microsoft.CmdPal.UI.ViewModels.Services;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.UI.Xaml.Controls;
 
@@ -19,7 +20,8 @@ public sealed partial class FallbackRanker : UserControl
 
         var settings = App.Current.Services.GetService<SettingsModel>()!;
         var topLevelCommandManager = App.Current.Services.GetService<TopLevelCommandManager>()!;
-        viewModel = new SettingsViewModel(settings, topLevelCommandManager, _mainTaskScheduler);
+        var themeService = App.Current.Services.GetService<IThemeService>()!;
+        viewModel = new SettingsViewModel(settings, topLevelCommandManager, _mainTaskScheduler, themeService);
     }
 
     private void ListView_DragItemsCompleted(ListViewBase sender, DragItemsCompletedEventArgs args)

src/modules/cmdpal/Microsoft.CmdPal.UI/Controls/ScreenPreview.xaml

@@ -0,0 +1,34 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<UserControl
+    x:Class="Microsoft.CmdPal.UI.Controls.ScreenPreview"
+    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
+    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
+    mc:Ignorable="d">
+
+    <Border
+        x:Name="ScreenBorder"
+        HorizontalAlignment="Center"
+        VerticalAlignment="Center"
+        BorderBrush="Black"
+        BorderThickness="8"
+        CornerRadius="8"
+        UseLayoutRounding="True">
+        <Viewbox Height="120" UseLayoutRounding="True">
+            <Grid>
+                <Image
+                    x:Name="WallpaperImage"
+                    MaxHeight="200"
+                    Stretch="Uniform"
+                    UseLayoutRounding="True" />
+                <ContentPresenter
+                    x:Name="ContentPresenter"
+                    Margin="40"
+                    Content="{x:Bind PreviewContent}"
+                    UseLayoutRounding="True" />
+            </Grid>
+        </Viewbox>
+    </Border>
+
+</UserControl>

src/modules/cmdpal/Microsoft.CmdPal.UI/Controls/ScreenPreview.xaml.cs

@@ -0,0 +1,33 @@
+// Copyright (c) Microsoft Corporation
+// The Microsoft Corporation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using Microsoft.CmdPal.UI.Helpers;
+using Microsoft.UI.Xaml;
+using Microsoft.UI.Xaml.Controls;
+using Microsoft.UI.Xaml.Markup;
+using Microsoft.UI.Xaml.Media;
+
+namespace Microsoft.CmdPal.UI.Controls;
+
+[ContentProperty(Name = nameof(PreviewContent))]
+public sealed partial class ScreenPreview : UserControl
+{
+    public static readonly DependencyProperty PreviewContentProperty =
+        DependencyProperty.Register(nameof(PreviewContent), typeof(object), typeof(ScreenPreview), new PropertyMetadata(null!))!;
+
+    public object PreviewContent
+    {
+        get => GetValue(PreviewContentProperty)!;
+        set => SetValue(PreviewContentProperty, value);
+    }
+
+    public ScreenPreview()
+    {
+        InitializeComponent();
+
+        var wallpaperHelper = new WallpaperHelper();
+        WallpaperImage!.Source = wallpaperHelper.GetWallpaperImage()!;
+        ScreenBorder!.Background = new SolidColorBrush(wallpaperHelper.GetWallpaperColor());
+    }
+}

src/modules/cmdpal/Microsoft.CmdPal.UI/Controls/SearchBar.xaml

@@ -4,9 +4,8 @@
     xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
     xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
     xmlns:cmdpalUi="using:Microsoft.CmdPal.UI"
-    xmlns:converters="using:CommunityToolkit.WinUI.Converters"
-    xmlns:cpcontrols="using:Microsoft.CmdPal.UI.Controls"
     xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
+    xmlns:h="using:Microsoft.CmdPal.UI.Helpers"
     xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
     mc:Ignorable="d">
 
@@ -22,6 +21,7 @@
         MinHeight="32"
         VerticalAlignment="Stretch"
         VerticalContentAlignment="Stretch"
+        h:TextBoxCaretColor.SyncWithForeground="True"
         AutomationProperties.AutomationId="MainSearchBox"
         KeyDown="FilterBox_KeyDown"
         PlaceholderText="{x:Bind CurrentPageViewModel.PlaceholderText, Converter={StaticResource PlaceholderTextConverter}, Mode=OneWay}"

src/modules/cmdpal/Microsoft.CmdPal.UI/Converters/ContrastBrushConverter.cs

@@ -0,0 +1,121 @@
+// Copyright (c) Microsoft Corporation
+// The Microsoft Corporation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using Microsoft.UI;
+using Microsoft.UI.Xaml;
+using Microsoft.UI.Xaml.Data;
+using Microsoft.UI.Xaml.Media;
+using Windows.UI;
+
+namespace Microsoft.CmdPal.UI.Converters;
+
+/// <summary>
+/// Gets a color, either black or white, depending on the brightness of the supplied color.
+/// </summary>
+public sealed partial class ContrastBrushConverter : IValueConverter
+{
+    /// <summary>
+    /// Gets or sets the alpha channel threshold below which a default color is used instead of black/white.
+    /// </summary>
+    public byte AlphaThreshold { get; set; } = 128;
+
+    /// <inheritdoc />
+    public object Convert(
+        object value,
+        Type targetType,
+        object parameter,
+        string language)
+    {
+        Color comparisonColor;
+        Color? defaultColor = null;
+
+        // Get the changing color to compare against
+        if (value is Color valueColor)
+        {
+            comparisonColor = valueColor;
+        }
+        else if (value is SolidColorBrush valueBrush)
+        {
+            comparisonColor = valueBrush.Color;
+        }
+        else
+        {
+            // Invalid color value provided
+            return DependencyProperty.UnsetValue;
+        }
+
+        // Get the default color when transparency is high
+        if (parameter is Color parameterColor)
+        {
+            defaultColor = parameterColor;
+        }
+        else if (parameter is SolidColorBrush parameterBrush)
+        {
+            defaultColor = parameterBrush.Color;
+        }
+
+        if (comparisonColor.A < AlphaThreshold &&
+            defaultColor.HasValue)
+        {
+            // If the transparency is less than 50 %, just use the default brush
+            // This can commonly be something like the TextControlForeground brush
+            return new SolidColorBrush(defaultColor.Value);
+        }
+        else
+        {
+            // Chose a white/black brush based on contrast to the base color
+            return UseLightContrastColor(comparisonColor)
+                ? new SolidColorBrush(Colors.White)
+                : new SolidColorBrush(Colors.Black);
+        }
+    }
+
+    /// <inheritdoc />
+    public object ConvertBack(
+        object value,
+        Type targetType,
+        object parameter,
+        string language)
+    {
+        return DependencyProperty.UnsetValue;
+    }
+
+    /// <summary>
+    /// Determines whether a light or dark contrast color should be used with the given displayed color.
+    /// </summary>
+    /// <remarks>
+    /// This code is using the WinUI algorithm.
+    /// </remarks>
+    private bool UseLightContrastColor(Color displayedColor)
+    {
+        // The selection ellipse should be light if and only if the chosen color
+        // contrasts more with black than it does with white.
+        // To find how much something contrasts with white, we use the equation
+        // for relative luminance, which is given by
+        //
+        // L = 0.2126 * Rg + 0.7152 * Gg + 0.0722 * Bg
+        //
+        // where Xg = { X/3294 if X <= 10, (R/269 + 0.0513)^2.4 otherwise }
+        //
+        // If L is closer to 1, then the color is closer to white; if it is closer to 0,
+        // then the color is closer to black.  This is based on the fact that the human
+        // eye perceives green to be much brighter than red, which in turn is perceived to be
+        // brighter than blue.
+        //
+        // If the third dimension is value, then we won't be updating the spectrum's displayed colors,
+        // so in that case we should use a value of 1 when considering the backdrop
+        // for the selection ellipse.
+        var rg = displayedColor.R <= 10
+            ? displayedColor.R / 3294.0
+            : Math.Pow((displayedColor.R / 269.0) + 0.0513, 2.4);
+        var gg = displayedColor.G <= 10
+            ? displayedColor.G / 3294.0
+            : Math.Pow((displayedColor.G / 269.0) + 0.0513, 2.4);
+        var bg = displayedColor.B <= 10
+            ? displayedColor.B / 3294.0
+            : Math.Pow((displayedColor.B / 269.0) + 0.0513, 2.4);
+
+        return (0.2126 * rg) + (0.7152 * gg) + (0.0722 * bg) <= 0.5;
+    }
+}

src/modules/cmdpal/Microsoft.CmdPal.UI/Converters/DetailsSizeToGridLengthConverter.cs

@@ -0,0 +1,39 @@
+// Copyright (c) Microsoft Corporation
+// The Microsoft Corporation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using Microsoft.CommandPalette.Extensions;
+using Microsoft.UI.Xaml;
+using Microsoft.UI.Xaml.Data;
+
+namespace Microsoft.CmdPal.UI;
+
+public partial class DetailsSizeToGridLengthConverter : IValueConverter
+{
+    public object Convert(object value, Type targetType, object parameter, string language)
+    {
+        if (value is ContentSize size)
+        {
+            // This converter calculates the Star width for the LIST.
+            //
+            // The input 'size' (ContentSize) represents the TARGET WIDTH desired for the DETAILS PANEL.
+            //
+            // To ensure the Details Panel achieves its target size (e.g. ContentSize.Large),
+            // we must shrink the List and let the Details fill the available space.
+            // (e.g., A larger target size for Details results in a smaller Star value for the List).
+            var starValue = size switch
+            {
+                ContentSize.Small => 3.0,
+                ContentSize.Medium => 2.0,
+                ContentSize.Large => 1.0,
+                _ => 3.0,
+            };
+
+            return new GridLength(starValue, GridUnitType.Star);
+        }
+
+        return new GridLength(3.0, GridUnitType.Star);
+    }
+
+    public object ConvertBack(object value, Type targetType, object parameter, string language) => throw new NotImplementedException();
+}

src/modules/cmdpal/Microsoft.CmdPal.UI/Helpers/BindTransformers.cs

@@ -10,6 +10,8 @@ internal static class BindTransformers
 {
     public static bool Negate(bool value) => !value;
 
+    public static Visibility NegateVisibility(Visibility value) => value == Visibility.Visible ? Visibility.Collapsed : Visibility.Visible;
+
     public static Visibility EmptyToCollapsed(string? input)
         => string.IsNullOrEmpty(input) ? Visibility.Collapsed : Visibility.Visible;
 

src/modules/cmdpal/Microsoft.CmdPal.UI/Helpers/ColorExtensions.cs

@@ -0,0 +1,132 @@
+// Copyright (c) Microsoft Corporation
+// The Microsoft Corporation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using CommunityToolkit.WinUI.Helpers;
+using Windows.UI;
+
+namespace Microsoft.CmdPal.UI.Helpers;
+
+/// <summary>
+/// Extension methods for <see cref="Color"/>.
+/// </summary>
+internal static class ColorExtensions
+{
+    /// <param name="color">Input color.</param>
+    public static double CalculateBrightness(this Color color)
+    {
+        return color.ToHsv().V;
+    }
+
+    /// <summary>
+    /// Allows to change the brightness by a factor based on the HSV color space.
+    /// </summary>
+    /// <param name="color">Input color.</param>
+    /// <param name="brightnessFactor">The brightness adjustment factor, ranging from -1 to 1.</param>
+    /// <returns>Updated color.</returns>
+    public static Color UpdateBrightness(this Color color, double brightnessFactor)
+    {
+        ArgumentOutOfRangeException.ThrowIfGreaterThan(brightnessFactor, 1);
+        ArgumentOutOfRangeException.ThrowIfLessThan(brightnessFactor, -1);
+
+        var hsvColor = color.ToHsv();
+        return ColorHelper.FromHsv(hsvColor.H, hsvColor.S, Math.Clamp(hsvColor.V + brightnessFactor, 0, 1), hsvColor.A);
+    }
+
+    /// <summary>
+    /// Updates the color by adjusting brightness, saturation, and luminance factors.
+    /// </summary>
+    /// <param name="color">Input color.</param>
+    /// <param name="brightnessFactor">The brightness adjustment factor, ranging from -1 to 1.</param>
+    /// <param name="saturationFactor">The saturation adjustment factor, ranging from -1 to 1. Defaults to 0.</param>
+    /// <param name="luminanceFactor">The luminance adjustment factor, ranging from -1 to 1. Defaults to 0.</param>
+    /// <returns>Updated color.</returns>
+    public static Color Update(this Color color, double brightnessFactor, double saturationFactor = 0, double luminanceFactor = 0)
+    {
+        ArgumentOutOfRangeException.ThrowIfGreaterThan(brightnessFactor, 1);
+        ArgumentOutOfRangeException.ThrowIfLessThan(brightnessFactor, -1);
+
+        ArgumentOutOfRangeException.ThrowIfGreaterThan(saturationFactor, 1);
+        ArgumentOutOfRangeException.ThrowIfLessThan(saturationFactor, -1);
+
+        ArgumentOutOfRangeException.ThrowIfGreaterThan(luminanceFactor, 1);
+        ArgumentOutOfRangeException.ThrowIfLessThan(luminanceFactor, -1);
+
+        var hsv = color.ToHsv();
+
+        var rgb = ColorHelper.FromHsv(
+            hsv.H,
+            Clamp01(hsv.S + saturationFactor),
+            Clamp01(hsv.V + brightnessFactor));
+
+        if (luminanceFactor == 0)
+        {
+            return rgb;
+        }
+
+        var hsl = rgb.ToHsl();
+        var lightness = Clamp01(hsl.L + luminanceFactor);
+        return ColorHelper.FromHsl(hsl.H, hsl.S, lightness);
+    }
+
+    /// <summary>
+    /// Linearly interpolates between two colors in HSV space.
+    /// Hue is blended along the shortest arc on the color wheel (wrap-aware).
+    /// Saturation, Value, and Alpha are blended linearly.
+    /// </summary>
+    /// <param name="a">Start color.</param>
+    /// <param name="b">End color.</param>
+    /// <param name="t">Interpolation factor in [0,1].</param>
+    /// <returns>Interpolated color.</returns>
+    public static Color LerpHsv(this Color a, Color b, double t)
+    {
+        t = Clamp01(t);
+
+        // Convert to HSV
+        var hslA = a.ToHsv();
+        var hslB = b.ToHsv();
+
+        var h1 = hslA.H;
+        var h2 = hslB.H;
+
+        // Handle near-gray hues (undefined hue) by inheriting the other's hue
+        const double satEps = 1e-4f;
+        if (hslA.S < satEps && hslB.S >= satEps)
+        {
+            h1 = h2;
+        }
+        else if (hslB.S < satEps && hslA.S >= satEps)
+        {
+            h2 = h1;
+        }
+
+        return ColorHelper.FromHsv(
+            hue: LerpHueDegrees(h1, h2, t),
+            saturation: Lerp(hslA.S, hslB.S, t),
+            value: Lerp(hslA.V, hslB.V, t),
+            alpha: (byte)Math.Round(Lerp(hslA.A, hslB.A, t)));
+    }
+
+    private static double LerpHueDegrees(double a, double b, double t)
+    {
+        a = Mod360(a);
+        b = Mod360(b);
+        var delta = ((b - a + 540f) % 360f) - 180f;
+        return Mod360(a + (delta * t));
+    }
+
+    private static double Mod360(double angle)
+    {
+        angle %= 360f;
+        if (angle < 0f)
+        {
+            angle += 360f;
+        }
+
+        return angle;
+    }
+
+    private static double Lerp(double a, double b, double t) => a + ((b - a) * t);
+
+    private static double Clamp01(double x) => Math.Clamp(x, 0, 1);
+}

src/modules/cmdpal/Microsoft.CmdPal.UI/Helpers/TextBoxCaretColor.cs

@@ -0,0 +1,173 @@
+// Copyright (c) Microsoft Corporation
+// The Microsoft Corporation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
+using CommunityToolkit.WinUI;
+using Microsoft.UI;
+using Microsoft.UI.Xaml;
+using Microsoft.UI.Xaml.Controls;
+using Microsoft.UI.Xaml.Media;
+using Rectangle = Microsoft.UI.Xaml.Shapes.Rectangle;
+
+namespace Microsoft.CmdPal.UI.Helpers;
+
+/// <summary>
+/// Attached property to color internal caret/overlay rectangles inside a TextBox
+/// so they follow the TextBox's actual Foreground brush.
+/// </summary>
+public static class TextBoxCaretColor
+{
+    public static readonly DependencyProperty SyncWithForegroundProperty =
+        DependencyProperty.RegisterAttached("SyncWithForeground", typeof(bool), typeof(TextBoxCaretColor), new PropertyMetadata(false, OnSyncCaretRectanglesChanged))!;
+
+    private static readonly ConditionalWeakTable<TextBox, State> States = [];
+
+    public static void SetSyncWithForeground(DependencyObject obj, bool value)
+    {
+        obj.SetValue(SyncWithForegroundProperty, value);
+    }
+
+    public static bool GetSyncWithForeground(DependencyObject obj)
+    {
+        return (bool)obj.GetValue(SyncWithForegroundProperty);
+    }
+
+    private static void OnSyncCaretRectanglesChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
+    {
+        if (d is not TextBox tb)
+        {
+            return;
+        }
+
+        if ((bool)e.NewValue)
+        {
+            Attach(tb);
+        }
+        else
+        {
+            Detach(tb);
+        }
+    }
+
+    private static void Attach(TextBox tb)
+    {
+        if (States.TryGetValue(tb, out var st) && st.IsHooked)
+        {
+            return;
+        }
+
+        st ??= new State();
+        st.IsHooked = true;
+        States.Remove(tb);
+        States.Add(tb, st);
+
+        tb.Loaded += TbOnLoaded;
+        tb.Unloaded += TbOnUnloaded;
+        tb.GotFocus += TbOnGotFocus;
+
+        st.ForegroundToken = tb.RegisterPropertyChangedCallback(Control.ForegroundProperty!, (_, _) => Apply(tb));
+
+        if (tb.IsLoaded)
+        {
+            Apply(tb);
+        }
+    }
+
+    private static void Detach(TextBox tb)
+    {
+        if (!States.TryGetValue(tb, out var st))
+        {
+            return;
+        }
+
+        tb.Loaded -= TbOnLoaded;
+        tb.Unloaded -= TbOnUnloaded;
+        tb.GotFocus -= TbOnGotFocus;
+
+        if (st.ForegroundToken != 0)
+        {
+            tb.UnregisterPropertyChangedCallback(Control.ForegroundProperty!, st.ForegroundToken);
+            st.ForegroundToken = 0;
+        }
+
+        st.IsHooked = false;
+    }
+
+    private static void TbOnLoaded(object sender, RoutedEventArgs e)
+    {
+        if (sender is TextBox tb)
+        {
+            Apply(tb);
+        }
+    }
+
+    private static void TbOnUnloaded(object sender, RoutedEventArgs e)
+    {
+        if (sender is TextBox tb)
+        {
+            Detach(tb);
+        }
+    }
+
+    private static void TbOnGotFocus(object sender, RoutedEventArgs e)
+    {
+        if (sender is TextBox tb)
+        {
+            Apply(tb);
+        }
+    }
+
+    private static void Apply(TextBox tb)
+    {
+        try
+        {
+            ApplyCore(tb);
+        }
+        catch (COMException)
+        {
+            // ignore
+        }
+    }
+
+    private static void ApplyCore(TextBox tb)
+    {
+        // Ensure template is realized
+        tb.ApplyTemplate();
+
+        // Find the internal ScrollContentPresenter within the TextBox template
+        var scp = tb.FindDescendant<ScrollContentPresenter>(s => s.Name == "ScrollContentPresenter");
+        if (scp is null)
+        {
+            return;
+        }
+
+        var brush = tb.Foreground; // use the actual current foreground brush
+        if (brush == null)
+        {
+            brush = new SolidColorBrush(Colors.Black);
+        }
+
+        foreach (var rect in scp.FindDescendants().OfType<Rectangle>())
+        {
+            try
+            {
+                rect.Fill = brush;
+                rect.CompositeMode = ElementCompositeMode.SourceOver;
+                rect.Opacity = 0.9;
+            }
+            catch
+            {
+                // best-effort; some rectangles might be template-owned
+            }
+        }
+    }
+
+    private sealed class State
+    {
+        public long ForegroundToken { get; set; }
+
+        public bool IsHooked { get; set; }
+    }
+}

src/modules/cmdpal/Microsoft.CmdPal.UI/Helpers/WallpaperHelper.cs

@@ -0,0 +1,178 @@
+// Copyright (c) Microsoft Corporation
+// The Microsoft Corporation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
+using System.Runtime.InteropServices.Marshalling;
+using ManagedCommon;
+using ManagedCsWin32;
+using Microsoft.UI;
+using Microsoft.UI.Xaml.Media.Imaging;
+using Windows.UI;
+
+namespace Microsoft.CmdPal.UI.Helpers;
+
+/// <summary>
+/// Lightweight helper to access wallpaper information.
+/// </summary>
+internal sealed partial class WallpaperHelper
+{
+    private readonly IDesktopWallpaper? _desktopWallpaper;
+
+    public WallpaperHelper()
+    {
+        try
+        {
+            var desktopWallpaper = ComHelper.CreateComInstance<IDesktopWallpaper>(
+                ref Unsafe.AsRef(in CLSID.DesktopWallpaper),
+                CLSCTX.ALL);
+
+            _desktopWallpaper = desktopWallpaper;
+        }
+        catch (Exception ex)
+        {
+            // If COM initialization fails, keep helper usable with safe fallbacks
+            Logger.LogError("Failed to initialize DesktopWallpaper COM interface", ex);
+            _desktopWallpaper = null;
+        }
+    }
+
+    private string? GetWallpaperPathForFirstMonitor()
+    {
+        try
+        {
+            if (_desktopWallpaper is null)
+            {
+                return null;
+            }
+
+            _desktopWallpaper.GetMonitorDevicePathCount(out var monitorCount);
+
+            for (uint i = 0; monitorCount != 0 && i < monitorCount; i++)
+            {
+                _desktopWallpaper.GetMonitorDevicePathAt(i, out var monitorId);
+                if (string.IsNullOrEmpty(monitorId))
+                {
+                    continue;
+                }
+
+                _desktopWallpaper.GetWallpaper(monitorId, out var wallpaperPath);
+
+                if (!string.IsNullOrWhiteSpace(wallpaperPath) && File.Exists(wallpaperPath))
+                {
+                    return wallpaperPath;
+                }
+            }
+        }
+        catch (Exception ex)
+        {
+            Logger.LogError("Failed to query wallpaper path", ex);
+        }
+
+        return null;
+    }
+
+    /// <summary>
+    /// Gets the wallpaper background color.
+    /// </summary>
+    /// <returns>The wallpaper background color, or black if it cannot be determined.</returns>
+    public Color GetWallpaperColor()
+    {
+        try
+        {
+            if (_desktopWallpaper is null)
+            {
+                return Colors.Black;
+            }
+
+            _desktopWallpaper.GetBackgroundColor(out var colorref);
+            var r = (byte)(colorref.Value & 0x000000FF);
+            var g = (byte)((colorref.Value & 0x0000FF00) >> 8);
+            var b = (byte)((colorref.Value & 0x00FF0000) >> 16);
+            return Color.FromArgb(255, r, g, b);
+        }
+        catch (Exception ex)
+        {
+            Logger.LogError("Failed to load wallpaper color", ex);
+            return Colors.Black;
+        }
+    }
+
+    /// <summary>
+    /// Gets the wallpaper image for the primary monitor.
+    /// </summary>
+    /// <returns>The wallpaper image, or null if it cannot be determined.</returns>
+    public BitmapImage? GetWallpaperImage()
+    {
+        try
+        {
+            var path = GetWallpaperPathForFirstMonitor();
+            if (string.IsNullOrWhiteSpace(path))
+            {
+                return null;
+            }
+
+            var image = new BitmapImage();
+            using var stream = File.OpenRead(path);
+            var randomAccessStream = stream.AsRandomAccessStream();
+            if (randomAccessStream == null)
+            {
+                Logger.LogError("Failed to convert file stream to RandomAccessStream for wallpaper image.");
+                return null;
+            }
+
+            image.SetSource(randomAccessStream);
+            return image;
+        }
+        catch (Exception ex)
+        {
+            Logger.LogError("Failed to load wallpaper image", ex);
+            return null;
+        }
+    }
+
+    // blittable type for COM interop
+    [StructLayout(LayoutKind.Sequential)]
+    internal readonly partial struct COLORREF
+    {
+        internal readonly uint Value;
+    }
+
+    // blittable type for COM interop
+    [StructLayout(LayoutKind.Sequential)]
+    internal readonly partial struct RECT
+    {
+        internal readonly int Left;
+        internal readonly int Top;
+        internal readonly int Right;
+        internal readonly int Bottom;
+    }
+
+    // COM interface for IDesktopWallpaper, GeneratedComInterface to be AOT compatible
+    [GeneratedComInterface]
+    [Guid("B92B56A9-8B55-4E14-9A89-0199BBB6F93B")]
+    [InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
+    internal partial interface IDesktopWallpaper
+    {
+        void SetWallpaper(
+            [MarshalAs(UnmanagedType.LPWStr)] string? monitorId,
+            [MarshalAs(UnmanagedType.LPWStr)] string wallpaper);
+
+        void GetWallpaper(
+            [MarshalAs(UnmanagedType.LPWStr)] string? monitorId,
+            [MarshalAs(UnmanagedType.LPWStr)] out string wallpaper);
+
+        void GetMonitorDevicePathAt(uint monitorIndex, [MarshalAs(UnmanagedType.LPWStr)] out string monitorId);
+
+        void GetMonitorDevicePathCount(out uint count);
+
+        void GetMonitorRECT([MarshalAs(UnmanagedType.LPWStr)] string? monitorId, out RECT rect);
+
+        void SetBackgroundColor(COLORREF color);
+
+        void GetBackgroundColor(out COLORREF color);
+
+        // Other methods omitted for brevity
+    }
+}

src/modules/cmdpal/Microsoft.CmdPal.UI/MainWindow.xaml

@@ -2,6 +2,7 @@
     x:Class="Microsoft.CmdPal.UI.MainWindow"
     xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
     xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+    xmlns:controls="using:Microsoft.CmdPal.UI.Controls"
     xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
     xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
     xmlns:pages="using:Microsoft.CmdPal.UI.Pages"
@@ -15,6 +16,21 @@
     Closed="MainWindow_Closed"
     mc:Ignorable="d">
     <Grid x:Name="RootElement">
+
+        <controls:BlurImageControl
+            HorizontalAlignment="Stretch"
+            VerticalAlignment="Stretch"
+            BlurAmount="{x:Bind ViewModel.BackgroundImageBlurAmount, Mode=OneWay}"
+            ImageBrightness="{x:Bind ViewModel.BackgroundImageBrightness, Mode=OneWay}"
+            ImageOpacity="{x:Bind ViewModel.BackgroundImageOpacity, Mode=OneWay}"
+            ImageSource="{x:Bind ViewModel.BackgroundImageSource, Mode=OneWay}"
+            ImageStretch="{x:Bind ViewModel.BackgroundImageStretch, Mode=OneWay}"
+            IsHitTestVisible="False"
+            IsHoldingEnabled="False"
+            TintColor="{x:Bind ViewModel.BackgroundImageTint, Mode=OneWay}"
+            TintIntensity="{x:Bind ViewModel.BackgroundImageTintIntensity, Mode=OneWay}"
+            Visibility="{x:Bind ViewModel.ShowBackgroundImage, Mode=OneWay}" />
+
         <pages:ShellPage />
     </Grid>
 </winuiex:WindowEx>

src/modules/cmdpal/Microsoft.CmdPal.UI/MainWindow.xaml.cs

@@ -15,8 +15,10 @@ using Microsoft.CmdPal.UI.Controls;
 using Microsoft.CmdPal.UI.Events;
 using Microsoft.CmdPal.UI.Helpers;
 using Microsoft.CmdPal.UI.Messages;
+using Microsoft.CmdPal.UI.Services;
 using Microsoft.CmdPal.UI.ViewModels;
 using Microsoft.CmdPal.UI.ViewModels.Messages;
+using Microsoft.CmdPal.UI.ViewModels.Services;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.PowerToys.Telemetry;
 using Microsoft.UI;
@@ -66,7 +68,10 @@ public sealed partial class MainWindow : WindowEx,
     private readonly KeyboardListener _keyboardListener;
     private readonly LocalKeyboardListener _localKeyboardListener;
     private readonly HiddenOwnerWindowBehavior _hiddenOwnerBehavior = new();
+    private readonly IThemeService _themeService;
+    private readonly WindowThemeSynchronizer _windowThemeSynchronizer;
     private bool _ignoreHotKeyWhenFullScreen = true;
+    private bool _themeServiceInitialized;
 
     private DesktopAcrylicController? _acrylicController;
     private SystemBackdropConfiguration? _configurationSource;
@@ -74,13 +79,21 @@ public sealed partial class MainWindow : WindowEx,
 
     private WindowPosition _currentWindowPosition = new();
 
+    private MainWindowViewModel ViewModel { get; }
+
     public MainWindow()
     {
         InitializeComponent();
 
+        ViewModel = App.Current.Services.GetService<MainWindowViewModel>()!;
+
         _autoGoHomeTimer = new DispatcherTimer();
         _autoGoHomeTimer.Tick += OnAutoGoHomeTimerOnTick;
 
+        _themeService = App.Current.Services.GetRequiredService<IThemeService>();
+        _themeService.ThemeChanged += ThemeServiceOnThemeChanged;
+        _windowThemeSynchronizer = new WindowThemeSynchronizer(_themeService, this);
+
         _hwnd = new HWND(WinRT.Interop.WindowNative.GetWindowHandle(this).ToInt32());
 
         unsafe
@@ -88,6 +101,8 @@ public sealed partial class MainWindow : WindowEx,
             CommandPaletteHost.SetHostHwnd((ulong)_hwnd.Value);
         }
 
+        SetAcrylic();
+
         _hiddenOwnerBehavior.ShowInTaskbar(this, Debugger.IsAttached);
 
         _keyboardListener = new KeyboardListener();
@@ -100,8 +115,6 @@ public sealed partial class MainWindow : WindowEx,
         RestoreWindowPosition();
         UpdateWindowPositionInMemory();
 
-        SetAcrylic();
-
         WeakReferenceMessenger.Default.Register<DismissMessage>(this);
         WeakReferenceMessenger.Default.Register<QuitMessage>(this);
         WeakReferenceMessenger.Default.Register<ShowWindowMessage>(this);
@@ -156,6 +169,11 @@ public sealed partial class MainWindow : WindowEx,
         WeakReferenceMessenger.Default.Send(new GoHomeMessage(WithAnimation: false, FocusSearch: false));
     }
 
+    private void ThemeServiceOnThemeChanged(object? sender, ThemeChangedEventArgs e)
+    {
+        UpdateAcrylic();
+    }
+
     private static void LocalKeyboardListener_OnKeyPressed(object? sender, LocalKeyboardListenerKeyPressedEventArgs e)
     {
         if (e.Key == VirtualKey.GoBack)
@@ -247,8 +265,6 @@ public sealed partial class MainWindow : WindowEx,
         _autoGoHomeTimer.Interval = _autoGoHomeInterval;
     }
 
-    // We want to use DesktopAcrylicKind.Thin and custom colors as this is the default material
-    // other Shell surfaces are using, this cannot be set in XAML however.
     private void SetAcrylic()
     {
         if (DesktopAcrylicController.IsSupported())
@@ -265,41 +281,32 @@ public sealed partial class MainWindow : WindowEx,
 
     private void UpdateAcrylic()
     {
-        if (_acrylicController != null)
+        try
         {
-            _acrylicController.RemoveAllSystemBackdropTargets();
-            _acrylicController.Dispose();
-        }
-
-        _acrylicController = GetAcrylicConfig(Content);
-
-        // Enable the system backdrop.
-        // Note: Be sure to have "using WinRT;" to support the Window.As<...>() call.
-        _acrylicController.AddSystemBackdropTarget(this.As<ICompositionSupportsSystemBackdrop>());
-        _acrylicController.SetSystemBackdropConfiguration(_configurationSource);
-    }
-
-    private static DesktopAcrylicController GetAcrylicConfig(UIElement content)
-    {
-        var feContent = content as FrameworkElement;
-
-        return feContent?.ActualTheme == ElementTheme.Light
-            ? new DesktopAcrylicController()
+            if (_acrylicController != null)
             {
-                Kind = DesktopAcrylicKind.Thin,
-                TintColor = Color.FromArgb(255, 243, 243, 243),
-                LuminosityOpacity = 0.90f,
-                TintOpacity = 0.0f,
-                FallbackColor = Color.FromArgb(255, 238, 238, 238),
+                _acrylicController.RemoveAllSystemBackdropTargets();
+                _acrylicController.Dispose();
             }
-            : new DesktopAcrylicController()
+
+            var backdrop = _themeService.Current.BackdropParameters;
+            _acrylicController = new DesktopAcrylicController
             {
-                Kind = DesktopAcrylicKind.Thin,
-                TintColor = Color.FromArgb(255, 32, 32, 32),
-                LuminosityOpacity = 0.96f,
-                TintOpacity = 0.5f,
-                FallbackColor = Color.FromArgb(255, 28, 28, 28),
+                TintColor = backdrop.TintColor,
+                TintOpacity = backdrop.TintOpacity,
+                FallbackColor = backdrop.FallbackColor,
+                LuminosityOpacity = backdrop.LuminosityOpacity,
             };
+
+            // Enable the system backdrop.
+            // Note: Be sure to have "using WinRT;" to support the Window.As<...>() call.
+            _acrylicController.AddSystemBackdropTarget(this.As<ICompositionSupportsSystemBackdrop>());
+            _acrylicController.SetSystemBackdropConfiguration(_configurationSource);
+        }
+        catch (Exception ex)
+        {
+            Logger.LogError("Failed to update backdrop", ex);
+        }
     }
 
     private void ShowHwnd(IntPtr hwndValue, MonitorBehavior target)
@@ -711,6 +718,19 @@ public sealed partial class MainWindow : WindowEx,
 
     internal void MainWindow_Activated(object sender, WindowActivatedEventArgs args)
     {
+        if (!_themeServiceInitialized && args.WindowActivationState != WindowActivationState.Deactivated)
+        {
+            try
+            {
+                _themeService.Initialize();
+                _themeServiceInitialized = true;
+            }
+            catch (Exception ex)
+            {
+                Logger.LogError("Failed to initialize ThemeService", ex);
+            }
+        }
+
         if (args.WindowActivationState == WindowActivationState.Deactivated)
         {
             // Save the current window position before hiding the window
@@ -1004,6 +1024,7 @@ public sealed partial class MainWindow : WindowEx,
     public void Dispose()
     {
         _localKeyboardListener.Dispose();
+        _windowThemeSynchronizer.Dispose();
         DisposeAcrylic();
     }
 }

src/modules/cmdpal/Microsoft.CmdPal.UI/Microsoft.CmdPal.UI.csproj

@@ -68,8 +68,11 @@
 
   <ItemGroup>
     <None Remove="Controls\ActionBar.xaml" />
+    <None Remove="Controls\ColorPalette.xaml" />
+    <None Remove="Controls\CommandPalettePreview.xaml" />
     <None Remove="Controls\DevRibbon.xaml" />
     <None Remove="Controls\KeyVisual\KeyCharPresenter.xaml" />
+    <None Remove="Controls\ScreenPreview.xaml" />
     <None Remove="Controls\SearchBar.xaml" />
     <None Remove="IsEnabledTextBlock.xaml" />
     <None Remove="ListDetailPage.xaml" />
@@ -78,10 +81,12 @@
     <None Remove="Pages\Settings\ExtensionsPage.xaml" />
     <None Remove="Pages\Settings\GeneralPage.xaml" />
     <None Remove="SettingsWindow.xaml" />
+    <None Remove="Settings\AppearancePage.xaml" />
     <None Remove="ShellPage.xaml" />
     <None Remove="Styles\Colors.xaml" />
     <None Remove="Styles\Settings.xaml" />
     <None Remove="Styles\TextBox.xaml" />
+    <None Remove="Styles\Theme.Normal.xaml" />
   </ItemGroup>
 
 
@@ -93,6 +98,7 @@
     <PackageReference Include="CommunityToolkit.WinUI.Extensions" />
     <PackageReference Include="CommunityToolkit.Labs.WinUI.Controls.MarkdownTextBlock" />
     <PackageReference Include="Microsoft.Extensions.DependencyInjection" />
+    <PackageReference Include="Microsoft.Graphics.Win2D" />
     <PackageReference Include="Microsoft.Windows.SDK.BuildTools" />
     <PackageReference Include="Microsoft.WindowsAppSDK" />
     <PackageReference Include="Microsoft.Xaml.Behaviors.WinUI.Managed" />
@@ -207,6 +213,39 @@
     </Content>
   </ItemGroup>
 
+  <ItemGroup>
+    <Page Update="Controls\CommandPalettePreview.xaml">
+      <Generator>MSBuild:Compile</Generator>
+    </Page>
+  </ItemGroup>
+
+  <ItemGroup>
+    <Page Update="Controls\ScreenPreview.xaml">
+      <Generator>MSBuild:Compile</Generator>
+    </Page>
+  </ItemGroup>
+
+  <ItemGroup>
+    <Page Update="Controls\ColorPalette.xaml">
+      <Generator>MSBuild:Compile</Generator>
+    </Page>
+  </ItemGroup>
+
+  <ItemGroup>
+    <Page Update="Styles\Theme.Colorful.xaml">
+      <SubType>Designer</SubType>
+    </Page>
+    <Page Update="Styles\Theme.Normal.xaml">
+      <Generator>MSBuild:Compile</Generator>
+    </Page>
+  </ItemGroup>
+
+  <ItemGroup>
+    <Page Update="Settings\AppearancePage.xaml">
+      <Generator>MSBuild:Compile</Generator>
+    </Page>
+  </ItemGroup>
+
   <ItemGroup>
     <Page Update="IsEnabledTextBlock.xaml">
       <Generator>MSBuild:Compile</Generator>

src/modules/cmdpal/Microsoft.CmdPal.UI/Pages/ShellPage.xaml

@@ -11,7 +11,6 @@
     xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
     xmlns:h="using:Microsoft.CmdPal.UI.Helpers"
     xmlns:help="using:Microsoft.CmdPal.UI.Helpers"
-    xmlns:labToolkit="using:CommunityToolkit.Labs.WinUI.MarkdownTextBlock"
     xmlns:markdownImageProviders="using:Microsoft.CmdPal.UI.Helpers.MarkdownImageProviders"
     xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
     xmlns:tkcontrols="using:CommunityToolkit.WinUI.Controls"
@@ -27,6 +26,7 @@
                 EmptyValue="Collapsed"
                 NotEmptyValue="Visible" />
 
+            <cmdpalUI:DetailsSizeToGridLengthConverter x:Key="SizeToWidthConverter" />
             <cmdpalUI:MessageStateToSeverityConverter x:Key="MessageStateToSeverityConverter" />
 
             <cmdpalUI:DetailsDataTemplateSelector
@@ -177,7 +177,7 @@
             <RowDefinition Height="Auto" />
         </Grid.RowDefinitions>
 
-        <Grid Background="{ThemeResource LayerOnAcrylicPrimaryBackgroundBrush}">
+        <Grid Grid.Row="0" Background="{ThemeResource LayerOnAcrylicPrimaryBackgroundBrush}">
             <Grid.RowDefinitions>
                 <RowDefinition Height="Auto" />
                 <RowDefinition Height="*" />
@@ -190,7 +190,7 @@
                 Padding="0,12,0,12"
                 HorizontalAlignment="Stretch"
                 VerticalAlignment="Stretch"
-                BorderBrush="{ThemeResource DividerStrokeColorDefaultBrush}"
+                BorderBrush="{ThemeResource CmdPal.TopBarBorderBrush}"
                 BorderThickness="0,0,0,1">
                 <Grid.ColumnDefinitions>
                     <ColumnDefinition Width="Auto" />
@@ -371,7 +371,7 @@
             <Grid x:Name="ContentGrid" Grid.Row="1">
 
                 <Grid.ColumnDefinitions>
-                    <ColumnDefinition Width="3*" />
+                    <ColumnDefinition Width="{x:Bind ViewModel.Details.Size, Mode=OneWay, Converter={StaticResource SizeToWidthConverter}}" />
                     <ColumnDefinition x:Name="DetailsColumn" Width="Auto" />
                 </Grid.ColumnDefinitions>
 
@@ -390,7 +390,7 @@
                     HorizontalAlignment="Stretch"
                     ui:VisualExtensions.NormalizedCenterPoint="0.5,0.5"
                     Background="{ThemeResource CardBackgroundFillColorDefaultBrush}"
-                    BorderBrush="{ThemeResource DividerStrokeColorDefaultBrush}"
+                    BorderBrush="{ThemeResource CmdPal.DividerStrokeColorDefaultBrush}"
                     BorderThickness="1"
                     CornerRadius="{StaticResource ControlCornerRadius}"
                     Visibility="Collapsed">
@@ -518,7 +518,7 @@
         <Grid
             Grid.Row="1"
             Background="{ThemeResource LayerOnAcrylicSecondaryBackgroundBrush}"
-            BorderBrush="{ThemeResource DividerStrokeColorDefaultBrush}"
+            BorderBrush="{ThemeResource CmdPal.DividerStrokeColorDefaultBrush}"
             BorderThickness="0,1,0,0">
             <cpcontrols:CommandBar CurrentPageViewModel="{x:Bind ViewModel.CurrentPage, Mode=OneWay}" />
         </Grid>

src/modules/cmdpal/Microsoft.CmdPal.UI/Services/ColorfulThemeProvider.cs

@@ -0,0 +1,207 @@
+// Copyright (c) Microsoft Corporation
+// The Microsoft Corporation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using CommunityToolkit.WinUI.Helpers;
+using Microsoft.CmdPal.UI.Helpers;
+using Microsoft.CmdPal.UI.ViewModels.Services;
+using Microsoft.UI.Xaml;
+using Windows.UI;
+using Windows.UI.ViewManagement;
+
+namespace Microsoft.CmdPal.UI.Services;
+
+/// <summary>
+/// Provides theme appropriate for colorful (accented) appearance.
+/// </summary>
+internal sealed class ColorfulThemeProvider : IThemeProvider
+{
+    // Fluent dark:  #202020
+    private static readonly Color DarkBaseColor = Color.FromArgb(255, 32, 32, 32);
+
+    // Fluent light: #F3F3F3
+    private static readonly Color LightBaseColor = Color.FromArgb(255, 243, 243, 243);
+
+    private readonly UISettings _uiSettings;
+
+    public string ThemeKey => "colorful";
+
+    public string ResourcePath => "ms-appx:///Styles/Theme.Colorful.xaml";
+
+    public ColorfulThemeProvider(UISettings uiSettings)
+    {
+        ArgumentNullException.ThrowIfNull(uiSettings);
+        _uiSettings = uiSettings;
+    }
+
+    public AcrylicBackdropParameters GetAcrylicBackdrop(ThemeContext context)
+    {
+        var isLight = context.Theme == ElementTheme.Light ||
+                      (context.Theme == ElementTheme.Default &&
+                       _uiSettings.GetColorValue(UIColorType.Background).R > 128);
+
+        var baseColor = isLight ? LightBaseColor : DarkBaseColor;
+
+        // Windows is warping the hue of accent colors and running it through some curves to produce their accent shades.
+        // This will attempt to mimic that behavior.
+        var accentShades = AccentShades.Compute(context.Tint.LerpHsv(WindowsAccentHueWarpTransform.Transform(context.Tint), 0.5f));
+        var blended = isLight ? accentShades.Light3 : accentShades.Dark2;
+        var colorIntensityUser = (context.ColorIntensity ?? 100) / 100f;
+
+        // For light theme, we want to reduce intensity a bit, and also we need to keep the color fairly light,
+        // to avoid issues with text box caret.
+        var colorIntensity = isLight ? 0.6f * colorIntensityUser : colorIntensityUser;
+        var effectiveBgColor = ColorBlender.Blend(baseColor, blended, colorIntensity);
+
+        return new AcrylicBackdropParameters(effectiveBgColor, effectiveBgColor, 0.8f, 0.8f);
+    }
+
+    private static class ColorBlender
+    {
+        /// <summary>
+        /// Blends a semitransparent tint color over an opaque base color using alpha compositing.
+        /// </summary>
+        /// <param name="baseColor">The opaque base color (background)</param>
+        /// <param name="tintColor">The semitransparent tint color (foreground)</param>
+        /// <param name="intensity">The intensity of the tint (0.0 - 1.0)</param>
+        /// <returns>The resulting blended color</returns>
+        public static Color Blend(Color baseColor, Color tintColor, float intensity)
+        {
+            // Normalize alpha to 0.0 - 1.0 range
+            intensity = Math.Clamp(intensity, 0f, 1f);
+
+            // Alpha compositing formula: result = tint * alpha + base * (1 - alpha)
+            var r = (byte)((tintColor.R * intensity) + (baseColor.R * (1 - intensity)));
+            var g = (byte)((tintColor.G * intensity) + (baseColor.G * (1 - intensity)));
+            var b = (byte)((tintColor.B * intensity) + (baseColor.B * (1 - intensity)));
+
+            // Result is fully opaque since base is opaque
+            return Color.FromArgb(255, r, g, b);
+        }
+    }
+
+    private static class WindowsAccentHueWarpTransform
+    {
+        private static readonly (double HIn, double HOut)[] HueMap =
+        [
+            (0, 0),
+            (10, 1),
+            (20, 6),
+            (30, 10),
+            (40, 14),
+            (50, 19),
+            (60, 36),
+            (70, 94),
+            (80, 112),
+            (90, 120),
+            (100, 120),
+            (110, 120),
+            (120, 120),
+            (130, 120),
+            (140, 120),
+            (150, 125),
+            (160, 135),
+            (170, 142),
+            (180, 178),
+            (190, 205),
+            (200, 220),
+            (210, 229),
+            (220, 237),
+            (230, 241),
+            (240, 243),
+            (250, 244),
+            (260, 245),
+            (270, 248),
+            (280, 252),
+            (290, 276),
+            (300, 293),
+            (310, 313),
+            (320, 330),
+            (330, 349),
+            (340, 353),
+            (350, 357)
+        ];
+
+        public static Color Transform(Color input, Options? opt = null)
+        {
+            opt ??= new Options();
+            var hsv = input.ToHsv();
+            return ColorHelper.FromHsv(
+                RemapHueLut(hsv.H),
+                Clamp01(Math.Pow(hsv.S, opt.SaturationGamma) * opt.SaturationGain),
+                Clamp01((opt.ValueScaleA * hsv.V) + opt.ValueBiasB),
+                input.A);
+        }
+
+        // Hue LUT remap (piecewise-linear with cyclic wrap)
+        private static double RemapHueLut(double hDeg)
+        {
+            // Normalize to [0,360)
+            hDeg = Mod(hDeg, 360.0);
+
+            // Handle wrap-around case: hDeg is between last entry (350°) and 360°
+            var last = HueMap[^1];
+            var first = HueMap[0];
+            if (hDeg >= last.HIn)
+            {
+                // Interpolate between last entry and first entry (wrapped by 360°)
+                var t = (hDeg - last.HIn) / (first.HIn + 360.0 - last.HIn + 1e-12);
+                var ho = Lerp(last.HOut, first.HOut + 360.0, t);
+                return Mod(ho, 360.0);
+            }
+
+            // Find segment [i, i+1] where HueMap[i].HIn <= hDeg < HueMap[i+1].HIn
+            for (var i = 0; i < HueMap.Length - 1; i++)
+            {
+                var a = HueMap[i];
+                var b = HueMap[i + 1];
+
+                if (hDeg >= a.HIn && hDeg < b.HIn)
+                {
+                    var t = (hDeg - a.HIn) / (b.HIn - a.HIn + 1e-12);
+                    return Lerp(a.HOut, b.HOut, t);
+                }
+            }
+
+            // Fallback (shouldn't happen)
+            return hDeg;
+        }
+
+        private static double Lerp(double a, double b, double t) => a + ((b - a) * t);
+
+        private static double Mod(double x, double m) => ((x % m) + m) % m;
+
+        private static double Clamp01(double x) => x < 0 ? 0 : (x > 1 ? 1 : x);
+
+        public sealed class Options
+        {
+            // Saturation boost (1.0 = no change). Typical: 1.3–1.8
+            public double SaturationGain { get; init; } = 1.0;
+
+            // Optional saturation gamma (1.0 = linear). <1.0 raises low S a bit; >1.0 preserves low S.
+            public double SaturationGamma { get; init; } = 1.0;
+
+            // Value (V) remap: V' = a*V + b   (tone curve; clamp applied)
+            // Example that lifts blacks & compresses whites slightly: a=0.50, b=0.08
+            public double ValueScaleA { get; init; } = 0.6;
+
+            public double ValueBiasB { get; init; } = 0.01;
+        }
+    }
+
+    private static class AccentShades
+    {
+        public static (Color Light3, Color Light2, Color Light1, Color Dark1, Color Dark2, Color Dark3) Compute(Color accent)
+        {
+            var light1 = accent.Update(brightnessFactor: 0.15, saturationFactor: -0.12);
+            var light2 = accent.Update(brightnessFactor: 0.30, saturationFactor: -0.24);
+            var light3 = accent.Update(brightnessFactor: 0.45, saturationFactor: -0.36);
+
+            var dark1 = accent.UpdateBrightness(brightnessFactor: -0.05f);
+            var dark2 = accent.UpdateBrightness(brightnessFactor: -0.01f);
+            var dark3 = accent.UpdateBrightness(brightnessFactor: -0.015f);
+
+            return (light3, light2, light1, dark1, dark2, dark3);
+        }
+    }
+}

src/modules/cmdpal/Microsoft.CmdPal.UI/Services/IThemeProvider.cs

@@ -0,0 +1,38 @@
+// Copyright (c) Microsoft Corporation
+// The Microsoft Corporation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using Microsoft.CmdPal.Core.Common.Services;
+using Microsoft.CmdPal.UI.ViewModels.Services;
+
+namespace Microsoft.CmdPal.UI.Services;
+
+/// <summary>
+/// Provides theme identification, resource path resolution, and creation of acrylic
+/// backdrop parameters based on the current <see cref="ThemeContext"/>.
+/// </summary>
+/// <remarks>
+/// Implementations should expose a stable <see cref="ThemeKey"/> and a valid XAML resource
+/// dictionary path via <see cref="ResourcePath"/>. The
+/// <see cref="GetAcrylicBackdrop(ThemeContext)"/> method computes
+/// <see cref="AcrylicBackdropParameters"/> using the supplied theme context.
+/// </remarks>
+internal interface IThemeProvider
+{
+    /// <summary>
+    /// Gets the unique key identifying this theme provider.
+    /// </summary>
+    string ThemeKey { get; }
+
+    /// <summary>
+    /// Gets the resource dictionary path for this theme.
+    /// </summary>
+    string ResourcePath { get; }
+
+    /// <summary>
+    /// Creates acrylic backdrop parameters based on the provided theme context.
+    /// </summary>
+    /// <param name="context">The current theme context, including theme, tint, and optional background details.</param>
+    /// <returns>The computed <see cref="AcrylicBackdropParameters"/> for the backdrop.</returns>
+    AcrylicBackdropParameters GetAcrylicBackdrop(ThemeContext context);
+}

src/modules/cmdpal/Microsoft.CmdPal.UI/Services/MutableOverridesDictionary.cs

@@ -0,0 +1,13 @@
+// Copyright (c) Microsoft Corporation
+// The Microsoft Corporation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using Microsoft.UI.Xaml;
+
+namespace Microsoft.CmdPal.UI.Services;
+
+/// <summary>
+/// Dedicated ResourceDictionary for dynamic overrides that win over base theme resources. Since
+/// we can't use a key or name to identify the dictionary in Application resources, we use a dedicated type.
+/// </summary>
+internal sealed partial class MutableOverridesDictionary : ResourceDictionary;

src/modules/cmdpal/Microsoft.CmdPal.UI/Services/NormalThemeProvider.cs

@@ -0,0 +1,43 @@
+// Copyright (c) Microsoft Corporation
+// The Microsoft Corporation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using Microsoft.CmdPal.UI.ViewModels.Services;
+using Microsoft.UI.Xaml;
+using Windows.UI;
+using Windows.UI.ViewManagement;
+
+namespace Microsoft.CmdPal.UI.Services;
+
+/// <summary>
+/// Provides theme resources and acrylic backdrop parameters matching the default Command Palette theme.
+/// </summary>
+internal sealed class NormalThemeProvider : IThemeProvider
+{
+    private static readonly Color DarkBaseColor = Color.FromArgb(255, 32, 32, 32);
+    private static readonly Color LightBaseColor = Color.FromArgb(255, 243, 243, 243);
+    private readonly UISettings _uiSettings;
+
+    public NormalThemeProvider(UISettings uiSettings)
+    {
+        ArgumentNullException.ThrowIfNull(uiSettings);
+        _uiSettings = uiSettings;
+    }
+
+    public string ThemeKey => "normal";
+
+    public string ResourcePath => "ms-appx:///Styles/Theme.Normal.xaml";
+
+    public AcrylicBackdropParameters GetAcrylicBackdrop(ThemeContext context)
+    {
+        var isLight = context.Theme == ElementTheme.Light ||
+                      (context.Theme == ElementTheme.Default &&
+                       _uiSettings.GetColorValue(UIColorType.Background).R > 128);
+
+        return new AcrylicBackdropParameters(
+            TintColor: isLight ? LightBaseColor : DarkBaseColor,
+            FallbackColor: isLight ? LightBaseColor : DarkBaseColor,
+            TintOpacity: 0.5f,
+            LuminosityOpacity: isLight ? 0.9f : 0.96f);
+    }
+}

src/modules/cmdpal/Microsoft.CmdPal.UI/Services/ResourceSwapper.cs

@@ -0,0 +1,332 @@
+// Copyright (c) Microsoft Corporation
+// The Microsoft Corporation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using Microsoft.UI.Xaml;
+
+namespace Microsoft.CmdPal.UI.Services;
+
+/// <summary>
+/// Simple theme switcher that swaps application ResourceDictionaries at runtime.
+/// Can also operate in event-only mode for consumers to apply resources themselves.
+/// Exposes a dedicated override dictionary that stays merged and is cleared on theme changes.
+/// </summary>
+internal sealed partial class ResourceSwapper
+{
+    private readonly Lock _resourceSwapGate = new();
+    private readonly Dictionary<string, Uri> _themeUris = new(StringComparer.OrdinalIgnoreCase);
+    private ResourceDictionary? _activeDictionary;
+    private string? _currentThemeName;
+    private Uri? _currentThemeUri;
+
+    private ResourceDictionary? _overrideDictionary;
+
+    /// <summary>
+    /// Raised after a theme has been activated.
+    /// </summary>
+    public event EventHandler<ResourcesSwappedEventArgs>? ResourcesSwapped;
+
+    /// <summary>
+    /// Gets or sets a value indicating whether when true (default) ResourceSwapper updates Application.Current.Resources. When false, it only raises ResourcesSwapped.
+    /// </summary>
+    public bool ApplyToAppResources { get; set; } = true;
+
+    /// <summary>
+    /// Gets name of the currently selected theme (if any).
+    /// </summary>
+    public string? CurrentThemeName
+    {
+        get
+        {
+            lock (_resourceSwapGate)
+            {
+                return _currentThemeName;
+            }
+        }
+    }
+
+    /// <summary>
+    /// Initializes ResourceSwapper by checking Application resources for an already merged theme dictionary.
+    /// </summary>
+    public void Initialize()
+    {
+        // Find merged dictionary in Application resources that matches a registered theme by URI
+        // This allows ResourceSwapper to pick up an initial theme set in XAML
+        var app = Application.Current;
+        var resourcesMergedDictionaries = app?.Resources?.MergedDictionaries;
+        if (resourcesMergedDictionaries == null)
+        {
+            return;
+        }
+
+        foreach (var dict in resourcesMergedDictionaries)
+        {
+            var uri = dict.Source;
+            if (uri is null)
+            {
+                continue;
+            }
+
+            var name = GetNameForUri(uri);
+            if (name is null)
+            {
+                continue;
+            }
+
+            lock (_resourceSwapGate)
+            {
+                _currentThemeName = name;
+                _currentThemeUri = uri;
+                _activeDictionary = dict;
+            }
+
+            break;
+        }
+    }
+
+    /// <summary>
+    /// Gets uri of the currently selected theme dictionary (if any).
+    /// </summary>
+    public Uri? CurrentThemeUri
+    {
+        get
+        {
+            lock (_resourceSwapGate)
+            {
+                return _currentThemeUri;
+            }
+        }
+    }
+
+    public static ResourceDictionary GetOverrideDictionary(bool clear = false)
+    {
+        var app = Application.Current ?? throw new InvalidOperationException("App is null");
+
+        if (app.Resources == null)
+        {
+            throw new InvalidOperationException("Application.Resources is null");
+        }
+
+        // (Re)locate the slot – Hot Reload may rebuild Application.Resources.
+        var slot = app.Resources!.MergedDictionaries!
+            .OfType<MutableOverridesDictionary>()
+            .FirstOrDefault();
+
+        if (slot is null)
+        {
+            // If the slot vanished (Hot Reload), create it again at the end so it wins precedence.
+            slot = new MutableOverridesDictionary();
+            app.Resources.MergedDictionaries!.Add(slot);
+        }
+
+        // Ensure the slot has exactly one child RD we can swap safely.
+        if (slot.MergedDictionaries!.Count == 0)
+        {
+            slot.MergedDictionaries.Add(new ResourceDictionary());
+        }
+        else if (slot.MergedDictionaries.Count > 1)
+        {
+            // Normalize to a single child to keep semantics predictable.
+            var keep = slot.MergedDictionaries[^1];
+            slot.MergedDictionaries.Clear();
+            slot.MergedDictionaries.Add(keep);
+        }
+
+        if (clear)
+        {
+            // Swap the child dictionary instead of Clear() to avoid reentrancy issues.
+            var fresh = new ResourceDictionary();
+            slot.MergedDictionaries[0] = fresh;
+            return fresh;
+        }
+
+        return slot.MergedDictionaries[0]!;
+    }
+
+    /// <summary>
+    /// Registers a theme name mapped to a XAML ResourceDictionary URI (e.g. ms-appx:///Themes/Red.xaml)
+    /// </summary>
+    public void RegisterTheme(string name, Uri dictionaryUri)
+    {
+        if (string.IsNullOrWhiteSpace(name))
+        {
+            throw new ArgumentException("Theme name is required", nameof(name));
+        }
+
+        lock (_resourceSwapGate)
+        {
+            _themeUris[name] = dictionaryUri ?? throw new ArgumentNullException(nameof(dictionaryUri));
+        }
+    }
+
+    /// <summary>
+    /// Registers a theme with a string URI.
+    /// </summary>
+    public void RegisterTheme(string name, string dictionaryUri)
+    {
+        ArgumentNullException.ThrowIfNull(dictionaryUri);
+        RegisterTheme(name, new Uri(dictionaryUri));
+    }
+
+    /// <summary>
+    /// Removes a previously registered theme.
+    /// </summary>
+    public bool UnregisterTheme(string name)
+    {
+        lock (_resourceSwapGate)
+        {
+            return _themeUris.Remove(name);
+        }
+    }
+
+    /// <summary>
+    /// Gets the names of all registered themes.
+    /// </summary>
+    public IEnumerable<string> GetRegisteredThemes()
+    {
+        lock (_resourceSwapGate)
+        {
+            // return a copy to avoid external mutation
+            return new List<string>(_themeUris.Keys);
+        }
+    }
+
+    /// <summary>
+    /// Activates a theme by name. The dictionary for the given name must be registered first.
+    /// </summary>
+    public void ActivateTheme(string theme)
+    {
+        if (string.IsNullOrWhiteSpace(theme))
+        {
+            throw new ArgumentException("Theme name is required", nameof(theme));
+        }
+
+        Uri uri;
+        lock (_resourceSwapGate)
+        {
+            if (!_themeUris.TryGetValue(theme, out uri!))
+            {
+                throw new KeyNotFoundException($"Theme '{theme}' is not registered.");
+            }
+        }
+
+        ActivateThemeInternal(theme, uri);
+    }
+
+    /// <summary>
+    /// Tries to activate a theme by name without throwing.
+    /// </summary>
+    public bool TryActivateTheme(string theme)
+    {
+        if (string.IsNullOrWhiteSpace(theme))
+        {
+            return false;
+        }
+
+        Uri uri;
+        lock (_resourceSwapGate)
+        {
+            if (!_themeUris.TryGetValue(theme, out uri!))
+            {
+                return false;
+            }
+        }
+
+        ActivateThemeInternal(theme, uri);
+        return true;
+    }
+
+    /// <summary>
+    /// Activates a theme by URI to a ResourceDictionary.
+    /// </summary>
+    public void ActivateTheme(Uri dictionaryUri)
+    {
+        ArgumentNullException.ThrowIfNull(dictionaryUri);
+
+        ActivateThemeInternal(GetNameForUri(dictionaryUri), dictionaryUri);
+    }
+
+    /// <summary>
+    /// Clears the currently active theme ResourceDictionary. Also clears the override dictionary.
+    /// </summary>
+    public void ClearActiveTheme()
+    {
+        lock (_resourceSwapGate)
+        {
+            var app = Application.Current;
+            if (app is null)
+            {
+                return;
+            }
+
+            if (_activeDictionary is not null && ApplyToAppResources)
+            {
+                _ = app.Resources.MergedDictionaries.Remove(_activeDictionary);
+                _activeDictionary = null;
+            }
+
+            // Clear overrides but keep the override dictionary merged for future updates
+            _overrideDictionary?.Clear();
+
+            _currentThemeName = null;
+            _currentThemeUri = null;
+        }
+    }
+
+    private void ActivateThemeInternal(string? name, Uri dictionaryUri)
+    {
+        lock (_resourceSwapGate)
+        {
+            _currentThemeName = name;
+            _currentThemeUri = dictionaryUri;
+        }
+
+        if (ApplyToAppResources)
+        {
+            ActivateThemeCore(dictionaryUri);
+        }
+
+        OnResourcesSwapped(new(name, dictionaryUri));
+    }
+
+    private void ActivateThemeCore(Uri dictionaryUri)
+    {
+        var app = Application.Current ?? throw new InvalidOperationException("Application.Current is null");
+
+        // Remove previously applied base theme dictionary
+        if (_activeDictionary is not null)
+        {
+            _ = app.Resources.MergedDictionaries.Remove(_activeDictionary);
+            _activeDictionary = null;
+        }
+
+        // Load and merge the new base theme dictionary
+        var newDict = new ResourceDictionary { Source = dictionaryUri };
+        app.Resources.MergedDictionaries.Add(newDict);
+        _activeDictionary = newDict;
+
+        // Ensure override dictionary exists and is merged last, then clear it to avoid leaking stale overrides
+        _overrideDictionary = GetOverrideDictionary(clear: true);
+    }
+
+    private string? GetNameForUri(Uri dictionaryUri)
+    {
+        lock (_resourceSwapGate)
+        {
+            foreach (var (key, value) in _themeUris)
+            {
+                if (Uri.Compare(value, dictionaryUri, UriComponents.AbsoluteUri, UriFormat.Unescaped, StringComparison.OrdinalIgnoreCase) == 0)
+                {
+                    return key;
+                }
+            }
+
+            return null;
+        }
+    }
+
+    private void OnResourcesSwapped(ResourcesSwappedEventArgs e)
+    {
+        ResourcesSwapped?.Invoke(this, e);
+    }
+}

src/modules/cmdpal/Microsoft.CmdPal.UI/Services/ResourcesSwappedEventArgs.cs

@@ -0,0 +1,12 @@
+// Copyright (c) Microsoft Corporation
+// The Microsoft Corporation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+namespace Microsoft.CmdPal.UI.Services;
+
+public sealed class ResourcesSwappedEventArgs(string? name, Uri dictionaryUri) : EventArgs
+{
+    public string? Name { get; } = name;
+
+    public Uri DictionaryUri { get; } = dictionaryUri ?? throw new ArgumentNullException(nameof(dictionaryUri));
+}

src/modules/cmdpal/Microsoft.CmdPal.UI/Services/ThemeContext.cs

@@ -0,0 +1,24 @@
+// Copyright (c) Microsoft Corporation
+// The Microsoft Corporation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using Microsoft.UI.Xaml;
+using Microsoft.UI.Xaml.Media;
+using Windows.UI;
+
+namespace Microsoft.CmdPal.UI.Services;
+
+internal sealed record ThemeContext
+{
+    public ElementTheme Theme { get; init; }
+
+    public Color Tint { get; init; }
+
+    public ImageSource? BackgroundImageSource { get; init; }
+
+    public Stretch BackgroundImageStretch { get; init; }
+
+    public double BackgroundImageOpacity { get; init; }
+
+    public int? ColorIntensity { get; init; }
+}

src/modules/cmdpal/Microsoft.CmdPal.UI/Services/ThemeService.cs

@@ -0,0 +1,261 @@
+// Copyright (c) Microsoft Corporation
+// The Microsoft Corporation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using CommunityToolkit.WinUI;
+using ManagedCommon;
+using Microsoft.CmdPal.UI.Helpers;
+using Microsoft.CmdPal.UI.ViewModels;
+using Microsoft.CmdPal.UI.ViewModels.Services;
+using Microsoft.UI;
+using Microsoft.UI.Dispatching;
+using Microsoft.UI.Xaml;
+using Microsoft.UI.Xaml.Media;
+using Microsoft.UI.Xaml.Media.Imaging;
+using Windows.UI.ViewManagement;
+using DispatcherQueue = Microsoft.UI.Dispatching.DispatcherQueue;
+
+namespace Microsoft.CmdPal.UI.Services;
+
+/// <summary>
+/// ThemeService is a hub that translates user settings and system preferences into concrete
+/// theme resources and notifies listeners of changes.
+/// </summary>
+internal sealed partial class ThemeService : IThemeService, IDisposable
+{
+    private static readonly TimeSpan ReloadDebounceInterval = TimeSpan.FromMilliseconds(500);
+
+    private readonly UISettings _uiSettings;
+    private readonly SettingsModel _settings;
+    private readonly ResourceSwapper _resourceSwapper;
+    private readonly NormalThemeProvider _normalThemeProvider;
+    private readonly ColorfulThemeProvider _colorfulThemeProvider;
+
+    private DispatcherQueue? _dispatcherQueue;
+    private DispatcherQueueTimer? _dispatcherQueueTimer;
+    private bool _isInitialized;
+    private bool _disposed;
+    private InternalThemeState _currentState;
+
+    public event EventHandler<ThemeChangedEventArgs>? ThemeChanged;
+
+    public ThemeSnapshot Current => Volatile.Read(ref _currentState).Snapshot;
+
+    /// <summary>
+    /// Initializes the theme service. Must be called after the application window is activated and on UI thread.
+    /// </summary>
+    public void Initialize()
+    {
+        if (_isInitialized)
+        {
+            return;
+        }
+
+        _dispatcherQueue = DispatcherQueue.GetForCurrentThread();
+        if (_dispatcherQueue is null)
+        {
+            throw new InvalidOperationException("Failed to get DispatcherQueue for the current thread. Ensure Initialize is called on the UI thread after window activation.");
+        }
+
+        _dispatcherQueueTimer = _dispatcherQueue.CreateTimer();
+
+        _resourceSwapper.Initialize();
+        _isInitialized = true;
+        Reload();
+    }
+
+    private void Reload()
+    {
+        if (!_isInitialized)
+        {
+            return;
+        }
+
+        // provider selection
+        var intensity = Math.Clamp(_settings.CustomThemeColorIntensity, 0, 100);
+        IThemeProvider provider = intensity > 0 && _settings.ColorizationMode is ColorizationMode.CustomColor or ColorizationMode.WindowsAccentColor or ColorizationMode.Image
+                ? _colorfulThemeProvider
+                : _normalThemeProvider;
+
+        // Calculate values
+        var tint = _settings.ColorizationMode switch
+        {
+            ColorizationMode.CustomColor => _settings.CustomThemeColor,
+            ColorizationMode.WindowsAccentColor => _uiSettings.GetColorValue(UIColorType.Accent),
+            ColorizationMode.Image => _settings.CustomThemeColor,
+            _ => Colors.Transparent,
+        };
+        var effectiveTheme = GetElementTheme((ElementTheme)_settings.Theme);
+        var imageSource = _settings.ColorizationMode == ColorizationMode.Image
+            ? LoadImageSafe(_settings.BackgroundImagePath)
+            : null;
+        var stretch = _settings.BackgroundImageFit switch
+        {
+            BackgroundImageFit.Fill => Stretch.Fill,
+            _ => Stretch.UniformToFill,
+        };
+        var opacity = Math.Clamp(_settings.BackgroundImageOpacity, 0, 100) / 100.0;
+
+        // create context and offload to actual theme provider
+        var context = new ThemeContext
+        {
+            Tint = tint,
+            ColorIntensity = intensity,
+            Theme = effectiveTheme,
+            BackgroundImageSource = imageSource,
+            BackgroundImageStretch = stretch,
+            BackgroundImageOpacity = opacity,
+        };
+        var backdrop = provider.GetAcrylicBackdrop(context);
+        var blur = _settings.BackgroundImageBlurAmount;
+        var brightness = _settings.BackgroundImageBrightness;
+
+        // Create public snapshot (no provider!)
+        var snapshot = new ThemeSnapshot
+        {
+            Tint = tint,
+            TintIntensity = intensity / 100f,
+            Theme = effectiveTheme,
+            BackgroundImageSource = imageSource,
+            BackgroundImageStretch = stretch,
+            BackgroundImageOpacity = opacity,
+            BackdropParameters = backdrop,
+            BlurAmount = blur,
+            BackgroundBrightness = brightness / 100f,
+        };
+
+        // Bundle with provider for internal use
+        var newState = new InternalThemeState
+        {
+            Snapshot = snapshot,
+            Provider = provider,
+        };
+
+        // Atomic swap
+        Interlocked.Exchange(ref _currentState, newState);
+
+        _resourceSwapper.TryActivateTheme(provider.ThemeKey);
+        ThemeChanged?.Invoke(this, new ThemeChangedEventArgs());
+    }
+
+    private static BitmapImage? LoadImageSafe(string? path)
+    {
+        if (string.IsNullOrWhiteSpace(path))
+        {
+            return null;
+        }
+
+        try
+        {
+            // If it looks like a file path and exists, prefer absolute file URI
+            if (!Uri.TryCreate(path, UriKind.RelativeOrAbsolute, out var uri))
+            {
+                return null;
+            }
+
+            if (!uri.IsAbsoluteUri && File.Exists(path))
+            {
+                uri = new Uri(Path.GetFullPath(path));
+            }
+
+            return new BitmapImage(uri);
+        }
+        catch (Exception ex)
+        {
+            Logger.LogWarning($"Failed to load background image '{path}'. {ex.Message}");
+            return null;
+        }
+    }
+
+    public ThemeService(SettingsModel settings, ResourceSwapper resourceSwapper)
+    {
+        ArgumentNullException.ThrowIfNull(settings);
+        ArgumentNullException.ThrowIfNull(resourceSwapper);
+
+        _settings = settings;
+        _settings.SettingsChanged += SettingsOnSettingsChanged;
+
+        _resourceSwapper = resourceSwapper;
+
+        _uiSettings = new UISettings();
+        _uiSettings.ColorValuesChanged += UiSettings_ColorValuesChanged;
+
+        _normalThemeProvider = new NormalThemeProvider(_uiSettings);
+        _colorfulThemeProvider = new ColorfulThemeProvider(_uiSettings);
+        List<IThemeProvider> providers = [_normalThemeProvider, _colorfulThemeProvider];
+
+        foreach (var provider in providers)
+        {
+            _resourceSwapper.RegisterTheme(provider.ThemeKey, provider.ResourcePath);
+        }
+
+        _currentState = new InternalThemeState
+        {
+            Snapshot = new ThemeSnapshot
+            {
+                Tint = Colors.Transparent,
+                Theme = ElementTheme.Light,
+                BackdropParameters = new AcrylicBackdropParameters(Colors.Black, Colors.Black, 0.5f, 0.5f),
+                BackgroundImageOpacity = 1,
+                BackgroundImageSource = null,
+                BackgroundImageStretch = Stretch.Fill,
+                BlurAmount = 0,
+                TintIntensity = 1.0f,
+                BackgroundBrightness = 0,
+            },
+            Provider = _normalThemeProvider,
+        };
+    }
+
+    private void RequestReload()
+    {
+        if (!_isInitialized || _dispatcherQueueTimer is null)
+        {
+            return;
+        }
+
+        _dispatcherQueueTimer.Debounce(Reload, ReloadDebounceInterval);
+    }
+
+    private ElementTheme GetElementTheme(ElementTheme theme)
+    {
+        return theme switch
+        {
+            ElementTheme.Light => ElementTheme.Light,
+            ElementTheme.Dark => ElementTheme.Dark,
+            _ => _uiSettings.GetColorValue(UIColorType.Background).CalculateBrightness() < 0.5
+                ? ElementTheme.Dark
+                : ElementTheme.Light,
+        };
+    }
+
+    private void SettingsOnSettingsChanged(SettingsModel sender, object? args)
+    {
+        RequestReload();
+    }
+
+    private void UiSettings_ColorValuesChanged(UISettings sender, object args)
+    {
+        RequestReload();
+    }
+
+    public void Dispose()
+    {
+        if (_disposed)
+        {
+            return;
+        }
+
+        _disposed = true;
+        _dispatcherQueueTimer?.Stop();
+        _uiSettings.ColorValuesChanged -= UiSettings_ColorValuesChanged;
+        _settings.SettingsChanged -= SettingsOnSettingsChanged;
+    }
+
+    private sealed class InternalThemeState
+    {
+        public required ThemeSnapshot Snapshot { get; init; }
+
+        public required IThemeProvider Provider { get; init; }
+    }
+}

src/modules/cmdpal/Microsoft.CmdPal.UI/Services/WindowThemeSynchronizer.cs

@@ -0,0 +1,70 @@
+// Copyright (c) Microsoft Corporation
+// The Microsoft Corporation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using Microsoft.CmdPal.Core.Common.Services;
+using Microsoft.CmdPal.UI.ViewModels.Services;
+using Microsoft.UI.Xaml;
+
+namespace Microsoft.CmdPal.UI.Services;
+
+/// <summary>
+/// Synchronizes a window's theme with <see cref="IThemeService"/>.
+/// </summary>
+internal sealed partial class WindowThemeSynchronizer : IDisposable
+{
+    private readonly IThemeService _themeService;
+    private readonly Window _window;
+
+    /// <summary>
+    /// Initializes a new instance of the <see cref="WindowThemeSynchronizer"/> class and subscribes to theme changes.
+    /// </summary>
+    /// <param name="themeService">The theme service to monitor for changes.</param>
+    /// <param name="window">The window to synchronize.</param>
+    /// <exception cref="ArgumentNullException">Thrown when <paramref name="themeService"/> or <paramref name="window"/> is null.</exception>
+    public WindowThemeSynchronizer(IThemeService themeService, Window window)
+    {
+        _themeService = themeService ?? throw new ArgumentNullException(nameof(themeService));
+        _window = window ?? throw new ArgumentNullException(nameof(window));
+        _themeService.ThemeChanged += ThemeServiceOnThemeChanged;
+    }
+
+    /// <summary>
+    /// Unsubscribes from theme change events.
+    /// </summary>
+    public void Dispose()
+    {
+        _themeService.ThemeChanged -= ThemeServiceOnThemeChanged;
+    }
+
+    /// <summary>
+    /// Applies the current theme to the window when theme changes occur.
+    /// </summary>
+    private void ThemeServiceOnThemeChanged(object? sender, ThemeChangedEventArgs e)
+    {
+        if (_window.Content is not FrameworkElement fe)
+        {
+            return;
+        }
+
+        var dispatcherQueue = fe.DispatcherQueue;
+
+        if (dispatcherQueue is not null && dispatcherQueue.HasThreadAccess)
+        {
+            ApplyRequestedTheme(fe);
+        }
+        else
+        {
+            dispatcherQueue?.TryEnqueue(() => ApplyRequestedTheme(fe));
+        }
+    }
+
+    private void ApplyRequestedTheme(FrameworkElement fe)
+    {
+        // LOAD BEARING: Changing the RequestedTheme to Dark then Light then target forces
+        // a refresh of the theme.
+        fe.RequestedTheme = ElementTheme.Dark;
+        fe.RequestedTheme = ElementTheme.Light;
+        fe.RequestedTheme = _themeService.Current.Theme;
+    }
+}

src/modules/cmdpal/Microsoft.CmdPal.UI/Settings/AppearancePage.xaml

@@ -0,0 +1,209 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<Page
+    x:Class="Microsoft.CmdPal.UI.Settings.AppearancePage"
+    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+    xmlns:controls="using:CommunityToolkit.WinUI.Controls"
+    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
+    xmlns:helpers="using:Microsoft.CmdPal.UI.Helpers"
+    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
+    xmlns:ptControls="using:Microsoft.CmdPal.UI.Controls"
+    xmlns:ui="using:CommunityToolkit.WinUI"
+    mc:Ignorable="d">
+    <Grid>
+        <Grid.RowDefinitions>
+            <RowDefinition Height="Auto" />
+            <RowDefinition Height="*" />
+        </Grid.RowDefinitions>
+        <ScrollViewer Grid.Row="1">
+            <Grid Padding="16">
+                <StackPanel
+                    MaxWidth="1000"
+                    HorizontalAlignment="Stretch"
+                    Spacing="{StaticResource SettingsCardSpacing}">
+
+                    <ptControls:ScreenPreview Margin="0,0,0,16" HorizontalAlignment="Left">
+                        <ptControls:CommandPalettePreview
+                            PreviewBackgroundColor="{x:Bind ViewModel.Appearance.EffectiveBackdrop.TintColor, Mode=OneWay}"
+                            PreviewBackgroundImageBlurAmount="{x:Bind ViewModel.Appearance.EffectiveBackgroundImageBlurAmount, Mode=OneWay}"
+                            PreviewBackgroundImageBrightness="{x:Bind ViewModel.Appearance.EffectiveBackgroundImageBrightness, Mode=OneWay}"
+                            PreviewBackgroundImageFit="{x:Bind ViewModel.Appearance.BackgroundImageFit, Mode=OneWay}"
+                            PreviewBackgroundImageSource="{x:Bind ViewModel.Appearance.EffectiveBackgroundImageSource, Mode=OneWay}"
+                            PreviewBackgroundImageTint="{x:Bind ViewModel.Appearance.EffectiveThemeColor, Mode=OneWay}"
+                            PreviewBackgroundImageTintIntensity="{x:Bind ViewModel.Appearance.ColorIntensity, Mode=OneWay}"
+                            PreviewBackgroundOpacity="{x:Bind ViewModel.Appearance.EffectiveBackdrop.TintOpacity, Mode=OneWay}"
+                            RequestedTheme="{x:Bind ViewModel.Appearance.EffectiveTheme, Mode=OneWay}" />
+                    </ptControls:ScreenPreview>
+
+                    <controls:SettingsCard x:Uid="Settings_GeneralPage_AppTheme_SettingsCard" HeaderIcon="{ui:FontIcon Glyph=&#xE793;}">
+                        <ComboBox MinWidth="{StaticResource SettingActionControlMinWidth}" SelectedIndex="{x:Bind ViewModel.Appearance.ThemeIndex, Mode=TwoWay}">
+
+                            <ComboBoxItem x:Uid="Settings_GeneralPage_AppTheme_Mode_System_Automation" Tag="Default">
+                                <StackPanel Orientation="Horizontal" Spacing="8">
+                                    <FontIcon FontSize="16" Glyph="&#xE770;" />
+                                    <TextBlock x:Uid="Settings_GeneralPage_AppTheme_Mode_System" />
+                                </StackPanel>
+                            </ComboBoxItem>
+
+                            <ComboBoxItem x:Uid="Settings_GeneralPage_AppTheme_Mode_Light_Automation" Tag="Light">
+                                <StackPanel Orientation="Horizontal" Spacing="8">
+                                    <FontIcon FontSize="16" Glyph="&#xE706;" />
+                                    <TextBlock x:Uid="Settings_GeneralPage_AppTheme_Mode_Light" />
+                                </StackPanel>
+                            </ComboBoxItem>
+
+                            <ComboBoxItem x:Uid="Settings_GeneralPage_AppTheme_Mode_Dark_Automation" Tag="Dark">
+                                <StackPanel Orientation="Horizontal" Spacing="8">
+                                    <FontIcon FontSize="16" Glyph="&#xE708;" />
+                                    <TextBlock x:Uid="Settings_GeneralPage_AppTheme_Mode_Dark" />
+                                </StackPanel>
+                            </ComboBoxItem>
+
+                        </ComboBox>
+                    </controls:SettingsCard>
+
+                    <controls:SettingsExpander
+                        x:Uid="Settings_GeneralPage_Background_SettingsExpander"
+                        HeaderIcon="{ui:FontIcon Glyph=&#xE790;}"
+                        IsExpanded="{x:Bind ViewModel.Appearance.IsColorizationDetailsExpanded, Mode=TwoWay}">
+                        <ComboBox
+                            x:Uid="Settings_GeneralPage_ColorizationMode"
+                            MinWidth="{StaticResource SettingActionControlMinWidth}"
+                            SelectedIndex="{x:Bind ViewModel.Appearance.ColorizationModeIndex, Mode=TwoWay}">
+                            <ComboBoxItem x:Uid="Settings_GeneralPage_ColorizationMode_None" />
+                            <ComboBoxItem x:Uid="Settings_GeneralPage_ColorizationMode_WindowsAccent" />
+                            <ComboBoxItem x:Uid="Settings_GeneralPage_ColorizationMode_CustomColor" />
+                            <ComboBoxItem x:Uid="Settings_GeneralPage_ColorizationMode_Image" />
+                        </ComboBox>
+                        <controls:SettingsExpander.Items>
+                            <!--  none  -->
+                            <controls:SettingsCard
+                                x:Uid="Settings_GeneralPage_NoBackground_SettingsCard"
+                                HorizontalContentAlignment="Stretch"
+                                ContentAlignment="Vertical"
+                                Visibility="{x:Bind ViewModel.Appearance.IsNoBackgroundVisible, Mode=OneWay}">
+                                <TextBlock
+                                    x:Uid="Settings_GeneralPage_NoBackground_DescriptionTextBlock"
+                                    Margin="24"
+                                    HorizontalAlignment="Stretch"
+                                    Foreground="{ThemeResource TextFillColorSecondaryBrush}"
+                                    HorizontalTextAlignment="Center"
+                                    TextAlignment="Center"
+                                    TextWrapping="WrapWholeWords" />
+                            </controls:SettingsCard>
+
+                            <!--  system accent color  -->
+                            <controls:SettingsCard x:Uid="Settings_GeneralPage_WindowsAccentColor_SettingsCard" Visibility="{x:Bind ViewModel.Appearance.IsAccentColorControlsVisible, Mode=OneWay}">
+                                <controls:SettingsCard.Description>
+                                    <TextBlock>
+                                        <Run x:Uid="Settings_GeneralPage_WindowsAccentColor_SettingsCard_Description1" />
+                                        <Hyperlink
+                                            Click="OpenWindowsColorsSettings_Click"
+                                            TextDecorations="None"
+                                            UnderlineStyle="None">
+                                            <Run x:Uid="Settings_GeneralPage_WindowsAccentColor_OpenWindowsColorsLinkText" />
+                                        </Hyperlink>
+                                    </TextBlock>
+                                </controls:SettingsCard.Description>
+                                <controls:SettingsCard.Content>
+                                    <Border
+                                        MinWidth="32"
+                                        MinHeight="32"
+                                        CornerRadius="{ThemeResource ControlCornerRadius}">
+                                        <Border.Background>
+                                            <SolidColorBrush Color="{x:Bind ViewModel.Appearance.EffectiveThemeColor, Mode=OneWay}" />
+                                        </Border.Background>
+                                    </Border>
+                                </controls:SettingsCard.Content>
+                            </controls:SettingsCard>
+
+                            <!--  background  -->
+                            <controls:SettingsCard
+                                x:Uid="Settings_GeneralPage_BackgroundImage_SettingsCard"
+                                Description="{x:Bind ViewModel.Appearance.BackgroundImagePath, Mode=OneWay}"
+                                Visibility="{x:Bind ViewModel.Appearance.IsBackgroundControlsVisible, Mode=OneWay}">
+                                <Button x:Uid="Settings_GeneralPage_BackgroundImage_ChooseImageButton" Click="PickBackgroundImage_Click" />
+                            </controls:SettingsCard>
+                            <controls:SettingsCard x:Uid="Settings_GeneralPage_BackgroundImageBrightness_SettingsCard" Visibility="{x:Bind ViewModel.Appearance.IsBackgroundControlsVisible, Mode=OneWay}">
+                                <Slider
+                                    MinWidth="{StaticResource SettingActionControlMinWidth}"
+                                    Maximum="100"
+                                    Minimum="-100"
+                                    StepFrequency="1"
+                                    Value="{x:Bind ViewModel.Appearance.BackgroundImageBrightness, Mode=TwoWay}" />
+                            </controls:SettingsCard>
+                            <controls:SettingsCard x:Uid="Settings_GeneralPage_BackgroundImageBlur_SettingsCard" Visibility="{x:Bind ViewModel.Appearance.IsBackgroundControlsVisible, Mode=OneWay}">
+                                <Slider
+                                    MinWidth="{StaticResource SettingActionControlMinWidth}"
+                                    Maximum="50"
+                                    Minimum="0"
+                                    StepFrequency="1"
+                                    Value="{x:Bind ViewModel.Appearance.BackgroundImageBlurAmount, Mode=TwoWay}" />
+                            </controls:SettingsCard>
+                            <controls:SettingsCard x:Uid="Settings_GeneralPage_BackgroundImageFit_SettingsCard" Visibility="{x:Bind ViewModel.Appearance.IsBackgroundControlsVisible, Mode=OneWay}">
+                                <ComboBox SelectedIndex="{x:Bind ViewModel.Appearance.BackgroundImageFitIndex, Mode=TwoWay}">
+                                    <ComboBoxItem x:Uid="BackgroundImageFit_ComboBoxItem_Fill" />
+                                    <ComboBoxItem x:Uid="BackgroundImageFit_ComboBoxItem_Stretch" />
+                                </ComboBox>
+                            </controls:SettingsCard>
+
+                            <!--  Background tint color and intensity  -->
+                            <controls:SettingsCard x:Uid="Settings_GeneralPage_BackgroundTint_SettingsCard" Visibility="{x:Bind ViewModel.Appearance.IsCustomTintVisible, Mode=OneWay}">
+                                <ptControls:ColorPickerButton
+                                    HasSelectedColor="True"
+                                    IsAlphaEnabled="False"
+                                    PaletteColors="{x:Bind ViewModel.Appearance.Swatches}"
+                                    SelectedColor="{x:Bind ViewModel.Appearance.ThemeColor, Mode=TwoWay}" />
+                            </controls:SettingsCard>
+                            <controls:SettingsCard x:Uid="Settings_GeneralPage_BackgroundTintIntensity_SettingsCard" Visibility="{x:Bind ViewModel.Appearance.IsCustomTintIntensityVisible, Mode=OneWay}">
+                                <Slider
+                                    MinWidth="{StaticResource SettingActionControlMinWidth}"
+                                    Maximum="100"
+                                    Minimum="1"
+                                    StepFrequency="1"
+                                    Value="{x:Bind ViewModel.Appearance.ColorIntensity, Mode=TwoWay}" />
+                            </controls:SettingsCard>
+
+                            <!--  Reset background image properties  -->
+                            <controls:SettingsCard x:Uid="Settings_GeneralPage_BackgroundImage_ResetProperties_SettingsCard" Visibility="{x:Bind ViewModel.Appearance.IsBackgroundControlsVisible, Mode=OneWay}">
+                                <StackPanel Orientation="Horizontal" Spacing="8">
+                                    <Button x:Uid="Settings_GeneralPage_Background_ResetImagePropertiesButton" Command="{x:Bind ViewModel.Appearance.ResetBackgroundImagePropertiesCommand}" />
+                                </StackPanel>
+                            </controls:SettingsCard>
+
+                        </controls:SettingsExpander.Items>
+                    </controls:SettingsExpander>
+
+                    <!--  'Behavior' section  -->
+
+                    <TextBlock x:Uid="BehaviorSettingsHeader" Style="{StaticResource SettingsSectionHeaderTextBlockStyle}" />
+
+                    <controls:SettingsCard x:Uid="Settings_GeneralPage_ShowAppDetails_SettingsCard" HeaderIcon="{ui:FontIcon Glyph=&#xE8A0;}">
+                        <ToggleSwitch IsOn="{x:Bind ViewModel.ShowAppDetails, Mode=TwoWay}" />
+                    </controls:SettingsCard>
+
+                    <controls:SettingsCard x:Uid="Settings_GeneralPage_BackspaceGoesBack_SettingsCard" HeaderIcon="{ui:FontIcon Glyph=&#xE750;}">
+                        <ToggleSwitch IsOn="{x:Bind ViewModel.BackspaceGoesBack, Mode=TwoWay}" />
+                    </controls:SettingsCard>
+
+                    <controls:SettingsCard x:Uid="Settings_GeneralPage_EscapeKeyBehavior_SettingsCard" HeaderIcon="{ui:FontIcon Glyph=&#xE845;}">
+                        <ComboBox MinWidth="{StaticResource SettingActionControlMinWidth}" SelectedIndex="{x:Bind ViewModel.EscapeKeyBehaviorIndex, Mode=TwoWay}">
+                            <ComboBoxItem x:Uid="Settings_GeneralPage_EscapeKeyBehavior_Option_DismissEmptySearchOrGoBack" />
+                            <ComboBoxItem x:Uid="Settings_GeneralPage_EscapeKeyBehavior_Option_AlwaysGoBack" />
+                            <ComboBoxItem x:Uid="Settings_GeneralPage_EscapeKeyBehavior_Option_AlwaysDismiss" />
+                            <ComboBoxItem x:Uid="Settings_GeneralPage_EscapeKeyBehavior_Option_AlwaysHide" />
+                        </ComboBox>
+                    </controls:SettingsCard>
+
+                    <controls:SettingsCard x:Uid="Settings_GeneralPage_SingleClickActivation_SettingsCard" HeaderIcon="{ui:FontIcon Glyph=&#xE962;}">
+                        <ToggleSwitch IsOn="{x:Bind ViewModel.SingleClickActivates, Mode=TwoWay}" />
+                    </controls:SettingsCard>
+
+                    <controls:SettingsCard x:Uid="Settings_GeneralPage_DisableAnimations_SettingsCard" HeaderIcon="{ui:FontIcon Glyph=&#xE945;}">
+                        <ToggleSwitch IsOn="{x:Bind ViewModel.DisableAnimations, Mode=TwoWay}" />
+                    </controls:SettingsCard>
+                </StackPanel>
+            </Grid>
+        </ScrollViewer>
+    </Grid>
+</Page>

src/modules/cmdpal/Microsoft.CmdPal.UI/Settings/AppearancePage.xaml.cs

@@ -0,0 +1,89 @@
+// Copyright (c) Microsoft Corporation
+// The Microsoft Corporation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System.Diagnostics;
+using ManagedCommon;
+using Microsoft.CmdPal.UI.ViewModels;
+using Microsoft.CmdPal.UI.ViewModels.Services;
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.UI;
+using Microsoft.UI.Xaml;
+using Microsoft.UI.Xaml.Controls;
+using Microsoft.UI.Xaml.Documents;
+using Microsoft.Windows.Storage.Pickers;
+
+namespace Microsoft.CmdPal.UI.Settings;
+
+/// <summary>
+/// An empty page that can be used on its own or navigated to within a Frame.
+/// </summary>
+public sealed partial class AppearancePage : Page
+{
+    private readonly TaskScheduler _mainTaskScheduler = TaskScheduler.FromCurrentSynchronizationContext();
+
+    internal SettingsViewModel ViewModel { get; }
+
+    public AppearancePage()
+    {
+        InitializeComponent();
+
+        var settings = App.Current.Services.GetService<SettingsModel>()!;
+        var themeService = App.Current.Services.GetService<IThemeService>()!;
+        var topLevelCommandManager = App.Current.Services.GetService<TopLevelCommandManager>()!;
+        ViewModel = new SettingsViewModel(settings, topLevelCommandManager, _mainTaskScheduler, themeService);
+    }
+
+    private async void PickBackgroundImage_Click(object sender, RoutedEventArgs e)
+    {
+        try
+        {
+            if (XamlRoot?.ContentIslandEnvironment is null)
+            {
+                return;
+            }
+
+            var windowId = XamlRoot?.ContentIslandEnvironment?.AppWindowId ?? new WindowId(0);
+
+            var picker = new FileOpenPicker(windowId)
+            {
+                CommitButtonText = ViewModels.Properties.Resources.builtin_settings_appearance_pick_background_image_title!,
+                SuggestedStartLocation = PickerLocationId.PicturesLibrary,
+                ViewMode = PickerViewMode.Thumbnail,
+            };
+
+            string[] extensions = [".png", ".bmp", ".jpg", ".jpeg", ".jfif", ".gif", ".tiff", ".tif", ".webp", ".jxr"];
+            foreach (var ext in extensions)
+            {
+                picker.FileTypeFilter!.Add(ext);
+            }
+
+            var file = await picker.PickSingleFileAsync()!;
+            if (file != null)
+            {
+                ViewModel.Appearance.BackgroundImagePath = file.Path ?? string.Empty;
+            }
+        }
+        catch (Exception ex)
+        {
+            Logger.LogError("Failed to pick background image file", ex);
+        }
+    }
+
+    private void OpenWindowsColorsSettings_Click(Hyperlink sender, HyperlinkClickEventArgs args)
+    {
+        // LOAD BEARING (or BEAR LOADING?): Process.Start with UseShellExecute inside a XAML input event can trigger WinUI reentrancy
+        // and cause FailFast crashes. Task.Run moves the call off the UI thread to prevent hard process termination.
+        Task.Run(() =>
+        {
+            try
+            {
+                _ = Process.Start(new ProcessStartInfo("ms-settings:colors") { UseShellExecute = true });
+            }
+            catch (Exception ex)
+            {
+                Logger.LogError("Failed to open Windows Settings", ex);
+            }
+        });
+    }
+}

src/modules/cmdpal/Microsoft.CmdPal.UI/Settings/ExtensionsPage.xaml.cs

@@ -5,6 +5,7 @@
 using CommunityToolkit.Mvvm.Messaging;
 using CommunityToolkit.WinUI.Controls;
 using Microsoft.CmdPal.UI.ViewModels;
+using Microsoft.CmdPal.UI.ViewModels.Services;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.UI.Xaml;
 using Microsoft.UI.Xaml.Controls;
@@ -24,7 +25,8 @@ public sealed partial class ExtensionsPage : Page
 
         var settings = App.Current.Services.GetService<SettingsModel>()!;
         var topLevelCommandManager = App.Current.Services.GetService<TopLevelCommandManager>()!;
-        viewModel = new SettingsViewModel(settings, topLevelCommandManager, _mainTaskScheduler);
+        var themeService = App.Current.Services.GetService<IThemeService>()!;
+        viewModel = new SettingsViewModel(settings, topLevelCommandManager, _mainTaskScheduler, themeService);
     }
 
     private void SettingsCard_Click(object sender, RoutedEventArgs e)

src/modules/cmdpal/Microsoft.CmdPal.UI/Settings/GeneralPage.xaml

@@ -81,35 +81,10 @@
 
                     <TextBlock x:Uid="BehaviorSettingsHeader" Style="{StaticResource SettingsSectionHeaderTextBlockStyle}" />
 
-                    <controls:SettingsCard x:Uid="Settings_GeneralPage_ShowAppDetails_SettingsCard" HeaderIcon="{ui:FontIcon Glyph=&#xE8A0;}">
-                        <ToggleSwitch IsOn="{x:Bind viewModel.ShowAppDetails, Mode=TwoWay}" />
-                    </controls:SettingsCard>
-
-                    <controls:SettingsCard x:Uid="Settings_GeneralPage_BackspaceGoesBack_SettingsCard" HeaderIcon="{ui:FontIcon Glyph=&#xE750;}">
-                        <ToggleSwitch IsOn="{x:Bind viewModel.BackspaceGoesBack, Mode=TwoWay}" />
-                    </controls:SettingsCard>
-
-                    <controls:SettingsCard x:Uid="Settings_GeneralPage_EscapeKeyBehavior_SettingsCard" HeaderIcon="{ui:FontIcon Glyph=&#xE845;}">
-                        <ComboBox MinWidth="{StaticResource SettingActionControlMinWidth}" SelectedIndex="{x:Bind viewModel.EscapeKeyBehaviorIndex, Mode=TwoWay}">
-                            <ComboBoxItem x:Uid="Settings_GeneralPage_EscapeKeyBehavior_Option_DismissEmptySearchOrGoBack" />
-                            <ComboBoxItem x:Uid="Settings_GeneralPage_EscapeKeyBehavior_Option_AlwaysGoBack" />
-                            <ComboBoxItem x:Uid="Settings_GeneralPage_EscapeKeyBehavior_Option_AlwaysDismiss" />
-                            <ComboBoxItem x:Uid="Settings_GeneralPage_EscapeKeyBehavior_Option_AlwaysHide" />
-                        </ComboBox>
-                    </controls:SettingsCard>
-
-                    <controls:SettingsCard x:Uid="Settings_GeneralPage_SingleClickActivation_SettingsCard" HeaderIcon="{ui:FontIcon Glyph=&#xE962;}">
-                        <ToggleSwitch IsOn="{x:Bind viewModel.SingleClickActivates, Mode=TwoWay}" />
-                    </controls:SettingsCard>
-
                     <controls:SettingsCard x:Uid="Settings_GeneralPage_ShowSystemTrayIcon_SettingsCard" HeaderIcon="{ui:FontIcon Glyph=&#xE75B;}">
                         <ToggleSwitch IsOn="{x:Bind viewModel.ShowSystemTrayIcon, Mode=TwoWay}" />
                     </controls:SettingsCard>
 
-                    <controls:SettingsCard x:Uid="Settings_GeneralPage_DisableAnimations_SettingsCard" HeaderIcon="{ui:FontIcon Glyph=&#xE945;}">
-                        <ToggleSwitch IsOn="{x:Bind viewModel.DisableAnimations, Mode=TwoWay}" />
-                    </controls:SettingsCard>
-
                     <!--  'For Developers' section  -->
 
                     <TextBlock x:Uid="ForDevelopersSettingsHeader" Style="{StaticResource SettingsSectionHeaderTextBlockStyle}" />

src/modules/cmdpal/Microsoft.CmdPal.UI/Settings/GeneralPage.xaml.cs

@@ -3,6 +3,7 @@
 // See the LICENSE file in the project root for more information.
 
 using Microsoft.CmdPal.UI.ViewModels;
+using Microsoft.CmdPal.UI.ViewModels.Services;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.UI.Xaml.Controls;
 using Windows.ApplicationModel;
@@ -21,7 +22,8 @@ public sealed partial class GeneralPage : Page
 
         var settings = App.Current.Services.GetService<SettingsModel>()!;
         var topLevelCommandManager = App.Current.Services.GetService<TopLevelCommandManager>()!;
-        viewModel = new SettingsViewModel(settings, topLevelCommandManager, _mainTaskScheduler);
+        var themeService = App.Current.Services.GetService<IThemeService>()!;
+        viewModel = new SettingsViewModel(settings, topLevelCommandManager, _mainTaskScheduler, themeService);
     }
 
     public string ApplicationVersion

src/modules/cmdpal/Microsoft.CmdPal.UI/Settings/SettingsWindow.xaml

@@ -62,6 +62,11 @@
                     x:Uid="Settings_GeneralPage_NavigationViewItem_General"
                     Icon="{ui:FontIcon Glyph=}"
                     Tag="General" />
+                <NavigationViewItem
+                    x:Name="AppearancePageNavItem"
+                    x:Uid="Settings_GeneralPage_NavigationViewItem_Appearance"
+                    Icon="{ui:FontIcon Glyph=&#xE790;}"
+                    Tag="Appearance" />
                 <NavigationViewItem
                     x:Name="ExtensionPageNavItem"
                     x:Uid="Settings_GeneralPage_NavigationViewItem_Extensions"

src/modules/cmdpal/Microsoft.CmdPal.UI/Settings/SettingsWindow.xaml.cs

@@ -101,6 +101,7 @@ public sealed partial class SettingsWindow : WindowEx,
         var pageType = page switch
         {
             "General" => typeof(GeneralPage),
+            "Appearance" => typeof(AppearancePage),
             "Extensions" => typeof(ExtensionsPage),
             _ => null,
         };
@@ -248,6 +249,12 @@ public sealed partial class SettingsWindow : WindowEx,
             var pageType = RS_.GetString("Settings_PageTitles_GeneralPage");
             BreadCrumbs.Add(new(pageType, pageType));
         }
+        else if (e.SourcePageType == typeof(AppearancePage))
+        {
+            NavView.SelectedItem = AppearancePageNavItem;
+            var pageType = RS_.GetString("Settings_PageTitles_AppearancePage");
+            BreadCrumbs.Add(new(pageType, pageType));
+        }
         else if (e.SourcePageType == typeof(ExtensionsPage))
         {
             NavView.SelectedItem = ExtensionPageNavItem;

src/modules/cmdpal/Microsoft.CmdPal.UI/Strings/en-us/Resources.resw

@@ -550,9 +550,69 @@ Right-click to remove the key combination, thereby deactivating the shortcut.</v
   <data name="Settings_GeneralPage_AutoGoHome_SettingsCard.Description" xml:space="preserve">
     <value>Automatically returns to home page after a period of inactivity when Command Palette is closed</value>
   </data>
+  <data name="Settings_GeneralPage_NavigationViewItem_Appearance.Content" xml:space="preserve">
+    <value>Personalization</value>
+  </data>
+  <data name="Settings_GeneralPage_AppTheme_SettingsCard.Header" xml:space="preserve">
+    <value>App theme mode</value>
+  </data>
+  <data name="Settings_GeneralPage_AppTheme_SettingsCard.Description" xml:space="preserve">
+    <value>Select which app theme to display</value>
+  </data>
+  <data name="AppearanceSettingsHeader.Text" xml:space="preserve">
+    <value>Appearance</value>
+  </data>
+  <data name="Settings_GeneralPage_AppTheme_Mode_System.Text" xml:space="preserve">
+    <value>Use system settings</value>
+  </data>
+  <data name="Settings_GeneralPage_AppTheme_Mode_Light.Text" xml:space="preserve">
+    <value>Light</value>
+  </data>
+  <data name="Settings_GeneralPage_AppTheme_Mode_Dark.Text" xml:space="preserve">
+    <value>Dark</value>
+  </data>
+  <data name="Settings_GeneralPage_BackgroundTint_SettingsCard.Header" xml:space="preserve">
+    <value>Color tint</value>
+  </data>
+  <data name="Settings_GeneralPage_BackgroundTintIntensity_SettingsCard.Header" xml:space="preserve">
+    <value>Color intensity</value>
+  </data>
+  <data name="OptionalColorPickerButton_UnsetTextBlock.Text" xml:space="preserve">
+    <value>Choose color</value>
+  </data>
+  <data name="OptionalColorPickerButton_ResetButton.Content" xml:space="preserve">
+    <value>Use default</value>
+  </data>
+  <data name="OptionalColorPickerButton_TransparentColorButton.Content" xml:space="preserve">
+    <value>Use default color</value>
+  </data>
+  <data name="OptionalColorPickerButton_WindowsColorsSectionHeading.Text" xml:space="preserve">
+    <value>Windows colors</value>
+  </data>
+  <data name="Settings_GeneralPage_BackgroundImage_SettingsExpander.Header" xml:space="preserve">
+    <value>Background image</value>
+  </data>
+  <data name="Settings_GeneralPage_BackgroundImageOpacity_SettingsCard.Header" xml:space="preserve">
+    <value>Background image opacity</value>
+  </data>
+  <data name="Settings_GeneralPage_BackgroundImageFit_SettingsCard.Header" xml:space="preserve">
+    <value>Background image fit</value>
+  </data>
+  <data name="BackgroundImageFit_ComboBoxItem_Fill.Content" xml:space="preserve">
+    <value>Fill</value>
+  </data>
+  <data name="BackgroundImageFit_ComboBoxItem_Fit.Content" xml:space="preserve">
+    <value>Fit</value>
+  </data>
+  <data name="BackgroundImageFit_ComboBoxItem_Stretch.Content" xml:space="preserve">
+    <value>Stretch</value>
+  </data>
   <data name="Settings_PageTitles_GeneralPage" xml:space="preserve">
     <value>General</value>
   </data>
+  <data name="Settings_PageTitles_AppearancePage" xml:space="preserve">
+    <value>Personalization</value>
+  </data>
   <data name="Settings_PageTitles_ExtensionsPage" xml:space="preserve">
     <value>Extensions</value>
   </data>
@@ -577,6 +637,75 @@ Right-click to remove the key combination, thereby deactivating the shortcut.</v
   <data name="SettingsButtonTextBlock.Text" xml:space="preserve">
     <value>Settings</value>
   </data>
+  <data name="OptionalColorPickerButton_CustomColorsSectionHeading.Text" xml:space="preserve">
+    <value>Custom colors</value>
+  </data>
+  <data name="Settings_GeneralPage_ColorizationMode_None.Content" xml:space="preserve">
+    <value>None</value>
+  </data>
+  <data name="Settings_GeneralPage_ColorizationMode_CustomColor.Content" xml:space="preserve">
+    <value>Custom color</value>
+  </data>
+  <data name="Settings_GeneralPage_ColorizationMode_WindowsAccent.Content" xml:space="preserve">
+    <value>Accent color</value>
+  </data>
+  <data name="Settings_GeneralPage_ColorizationMode_Image.Content" xml:space="preserve">
+    <value>Image</value>
+  </data>
+  <data name="Settings_GeneralPage_BackgroundImage_ChooseImageButton.Content" xml:space="preserve">
+    <value>Browse...</value>
+  </data>
+  <data name="Settings_GeneralPage_BackgroundImage_ResetImageButton.Content" xml:space="preserve">
+    <value>Remove image</value>
+  </data>
+  <data name="Settings_GeneralPage_BackgroundColor_SettingsExpander.Header" xml:space="preserve">
+    <value>Background color</value>
+  </data>
+  <data name="Settings_GeneralPage_BackgroundColor_SettingsExpander.Description" xml:space="preserve">
+    <value>Choose a custom background color or use the current accent color</value>
+  </data>
+  <data name="Settings_GeneralPage_BackgroundImage_SettingsCard.Header" xml:space="preserve">
+    <value>Background image</value>
+  </data>
+  <data name="Settings_GeneralPage_NoBackground_DescriptionTextBlock.Text" xml:space="preserve">
+    <value>No settings</value>
+  </data>
+  <data name="Settings_GeneralPage_Background_SettingsExpander.Header" xml:space="preserve">
+    <value>Background</value>
+  </data>
+  <data name="Settings_GeneralPage_Background_SettingsExpander.Description" xml:space="preserve">
+    <value>Choose a custom background color or image</value>
+  </data>
+  <data name="Settings_GeneralPage_WindowsAccentColor_SettingsCard.Header" xml:space="preserve">
+    <value>System accent color</value>
+  </data>
+  <data name="Settings_GeneralPage_WindowsAccentColor_OpenWindowsColorsLinkText.Text" xml:space="preserve">
+    <value>Personalization › Colors</value>
+  </data>
+  <data name="Settings_GeneralPage_BackgroundImageBlur_SettingsCard.Header" xml:space="preserve">
+    <value>Background image blur</value>
+  </data>
+  <data name="Settings_GeneralPage_BackgroundImageBrightness_SettingsCard.Header" xml:space="preserve">
+    <value>Background image brightness</value>
+  </data>
+  <data name="Settings_GeneralPage_BackgroundImage_ResetProperties_SettingsCard.Header" xml:space="preserve">
+    <value>Restore defaults</value>
+  </data>
+  <data name="Settings_GeneralPage_Background_ResetImagePropertiesButton.Content" xml:space="preserve">
+    <value>Reset</value>
+  </data>
+  <data name="Settings_GeneralPage_WindowsAccentColor_SettingsCard_Description1.Text" xml:space="preserve">
+    <value>Change the system accent in Windows Settings:</value>
+  </data>
+  <data name="Settings_GeneralPage_AppTheme_Mode_Light_Automation.[using:Microsoft.UI.Xaml.Automation]AutomationProperties.Name" xml:space="preserve">
+    <value>Light</value>
+  </data>
+  <data name="Settings_GeneralPage_AppTheme_Mode_Dark_Automation.[using:Microsoft.UI.Xaml.Automation]AutomationProperties.Name" xml:space="preserve">
+    <value>Dark</value>
+  </data>
+  <data name="Settings_GeneralPage_AppTheme_Mode_System_Automation.[using:Microsoft.UI.Xaml.Automation]AutomationProperties.Name" xml:space="preserve">
+    <value>Use system settings</value>
+  </data>
   <data name="Settings_FallbacksPage_GlobalResults_SettingsCard.Header" xml:space="preserve">
     <value>Include in the Global result</value>
   </data>

src/modules/cmdpal/Microsoft.CmdPal.UI/Styles/Colors.xaml

@@ -4,37 +4,5 @@
 
     <ResourceDictionary.MergedDictionaries>
         <XamlControlsResources xmlns="using:Microsoft.UI.Xaml.Controls" />
-        <!--  Other merged dictionaries here  -->
     </ResourceDictionary.MergedDictionaries>
-
-    <ResourceDictionary.ThemeDictionaries>
-        <!--  For slightly adjust the LayerOnAcrylicFillColorDefault color so that the cursor of the searchbox shows  -->
-        <ResourceDictionary x:Key="Default">
-            <!--  This is a local copy of LayerOnAcrylicFillColorDefaultBrush  -->
-            <SolidColorBrush
-                x:Key="LayerOnAcrylicPrimaryBackgroundBrush"
-                Opacity="0.3"
-                Color="#222222" />
-            <SolidColorBrush
-                x:Key="LayerOnAcrylicSecondaryBackgroundBrush"
-                Opacity="0.0"
-                Color="#222222" />
-        </ResourceDictionary>
-        <ResourceDictionary x:Key="Light">
-            <SolidColorBrush
-                x:Key="LayerOnAcrylicPrimaryBackgroundBrush"
-                Opacity="0.65"
-                Color="#FFFFFF" />
-            <!--  Because we are tweaking the LayerOnAcrylicPrimaryBackgroundBrush, we need to tweak the command bar background too. If not, it's too bright.  -->
-            <SolidColorBrush
-                x:Key="LayerOnAcrylicSecondaryBackgroundBrush"
-                Opacity="0.4"
-                Color="#FFFFFF" />
-        </ResourceDictionary>
-        <ResourceDictionary x:Key="HighContrast">
-            <!--  This is a local copy of LayerOnAcrylicFillColorDefaultBrush  -->
-            <SolidColorBrush x:Key="LayerOnAcrylicPrimaryBackgroundBrush" Color="{ThemeResource LayerOnAcrylicFillColorDefault}" />
-            <SolidColorBrush x:Key="LayerOnAcrylicSecondaryBackgroundBrush" Color="Transparent" />
-        </ResourceDictionary>
-    </ResourceDictionary.ThemeDictionaries>
 </ResourceDictionary>

src/modules/cmdpal/Microsoft.CmdPal.UI/Styles/Theme.Colorful.xaml

@@ -0,0 +1,28 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+
+    <ResourceDictionary.ThemeDictionaries>
+        <ResourceDictionary x:Key="Dark">
+            <StaticResource x:Key="LayerOnAcrylicPrimaryBackgroundBrush" ResourceKey="LayerOnAccentAcrylicFillColorDefaultBrush" />
+            <SolidColorBrush x:Key="LayerOnAcrylicSecondaryBackgroundBrush" Color="Transparent" />
+            <StaticResource x:Key="CmdPal.CommandBarBorderBrush" ResourceKey="CardStrokeColorDefaultBrush" />
+            <StaticResource x:Key="CmdPal.TopBarBorderBrush" ResourceKey="DividerStrokeColorDefaultBrush" />
+            <StaticResource x:Key="CmdPal.DividerStrokeColorDefaultBrush" ResourceKey="CardStrokeColorDefaultBrush" />
+        </ResourceDictionary>
+        <ResourceDictionary x:Key="Light">
+            <SolidColorBrush x:Key="LayerOnAcrylicPrimaryBackgroundBrush" Color="#A0FFFFFF" />
+            <SolidColorBrush x:Key="LayerOnAcrylicSecondaryBackgroundBrush" Color="Transparent" />
+            <StaticResource x:Key="CmdPal.CommandBarBorderBrush" ResourceKey="CardStrokeColorDefaultBrush" />
+            <StaticResource x:Key="CmdPal.TopBarBorderBrush" ResourceKey="DividerStrokeColorDefaultBrush" />
+            <StaticResource x:Key="CmdPal.DividerStrokeColorDefaultBrush" ResourceKey="CardStrokeColorDefaultBrush" />
+        </ResourceDictionary>
+        <ResourceDictionary x:Key="HighContrast">
+            <SolidColorBrush x:Key="LayerOnAcrylicPrimaryBackgroundBrush" Color="{ThemeResource SystemColorWindowColor}" />
+            <SolidColorBrush x:Key="LayerOnAcrylicSecondaryBackgroundBrush" Color="{ThemeResource SystemColorWindowColor}" />
+            <SolidColorBrush x:Key="CmdPal.CommandBarBorderBrush" Color="{ThemeResource SystemColorWindowTextColor}" />
+            <SolidColorBrush x:Key="CmdPal.TopBarBorderBrush" Color="{ThemeResource SystemColorWindowTextColor}" />
+            <SolidColorBrush x:Key="CmdPal.DividerStrokeColorDefaultBrush" Color="{ThemeResource SystemColorWindowTextColor}" />
+        </ResourceDictionary>
+    </ResourceDictionary.ThemeDictionaries>
+
+</ResourceDictionary>

src/modules/cmdpal/Microsoft.CmdPal.UI/Styles/Theme.Normal.xaml

@@ -0,0 +1,33 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+
+    <ResourceDictionary.ThemeDictionaries>
+        <ResourceDictionary x:Key="Dark">
+            <SolidColorBrush x:Key="LayerOnAcrylicPrimaryBackgroundBrush" Color="#50202020" />
+            <SolidColorBrush x:Key="LayerOnAcrylicSecondaryBackgroundBrush" Color="Transparent" />
+            <StaticResource x:Key="CmdPal.CommandBarBorderBrush" ResourceKey="DividerStrokeColorDefaultBrush" />
+            <StaticResource x:Key="CmdPal.TopBarBorderBrush" ResourceKey="DividerStrokeColorDefaultBrush" />
+            <StaticResource x:Key="CmdPal.DividerStrokeColorDefaultBrush" ResourceKey="DividerStrokeColorDefaultBrush" />
+        </ResourceDictionary>
+        <ResourceDictionary x:Key="Light">
+            <!--
+                TextBox caret is rendered as inverted and needs clearly-defined background
+                https://github.com/zadjii-msft/PowerToys/issues/348
+                Because we are tweaking the LayerOnAcrylicPrimaryBackgroundBrush, we need to tweak the command bar background too. If not, it's too bright.
+            -->
+            <SolidColorBrush x:Key="LayerOnAcrylicPrimaryBackgroundBrush" Color="#A0FFFFFF" />
+            <SolidColorBrush x:Key="LayerOnAcrylicSecondaryBackgroundBrush" Color="#66FFFFFF" />
+            <StaticResource x:Key="CmdPal.CommandBarBorderBrush" ResourceKey="DividerStrokeColorDefaultBrush" />
+            <StaticResource x:Key="CmdPal.TopBarBorderBrush" ResourceKey="DividerStrokeColorDefaultBrush" />
+            <StaticResource x:Key="CmdPal.DividerStrokeColorDefaultBrush" ResourceKey="DividerStrokeColorDefaultBrush" />
+        </ResourceDictionary>
+        <ResourceDictionary x:Key="HighContrast">
+            <SolidColorBrush x:Key="LayerOnAcrylicPrimaryBackgroundBrush" Color="{ThemeResource SystemColorWindowColor}" />
+            <SolidColorBrush x:Key="LayerOnAcrylicSecondaryBackgroundBrush" Color="{ThemeResource SystemColorWindowColor}" />
+            <SolidColorBrush x:Key="CmdPal.CommandBarBorderBrush" Color="{ThemeResource SystemColorWindowTextColor}" />
+            <SolidColorBrush x:Key="CmdPal.TopBarBorderBrush" Color="{ThemeResource SystemColorWindowTextColor}" />
+            <SolidColorBrush x:Key="CmdPal.DividerStrokeColorDefaultBrush" Color="{ThemeResource SystemColorWindowTextColor}" />
+        </ResourceDictionary>
+    </ResourceDictionary.ThemeDictionaries>
+
+</ResourceDictionary>

src/modules/cmdpal/Tests/Microsoft.CmdPal.UI.ViewModels.UnitTests/MainListPageResultFactoryTests.cs

@@ -0,0 +1,161 @@
+// Copyright (c) Microsoft Corporation
+// The Microsoft Corporation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using Microsoft.CmdPal.UI.ViewModels.Commands;
+using Microsoft.CommandPalette.Extensions;
+using Microsoft.CommandPalette.Extensions.Toolkit;
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+using Windows.Foundation;
+
+namespace Microsoft.CmdPal.UI.ViewModels.UnitTests;
+
+[TestClass]
+public partial class MainListPageResultFactoryTests
+{
+    private sealed partial class MockListItem : IListItem
+    {
+        public string Title { get; set; } = string.Empty;
+
+        public string Subtitle { get; set; } = string.Empty;
+
+        public ICommand Command => new NoOpCommand();
+
+        public IDetails? Details => null;
+
+        public IIconInfo? Icon => null;
+
+        public string Section => throw new NotImplementedException();
+
+        public ITag[] Tags => throw new NotImplementedException();
+
+        public string TextToSuggest => throw new NotImplementedException();
+
+        public IContextItem[] MoreCommands => throw new NotImplementedException();
+
+#pragma warning disable CS0067 // The event is never used
+        public event TypedEventHandler<object, IPropChangedEventArgs>? PropChanged;
+#pragma warning restore CS0067 // The event is never used
+
+        public override string ToString() => Title;
+    }
+
+    private static Scored<IListItem> S(string title, int score)
+    {
+        return new Scored<IListItem>
+        {
+            Score = score,
+            Item = new MockListItem { Title = title },
+        };
+    }
+
+    [TestMethod]
+    public void Merge_PrioritizesListsCorrectly()
+    {
+        var filtered = new List<Scored<IListItem>>
+        {
+            S("F1", 100),
+            S("F2", 50),
+        };
+
+        var scoredFallback = new List<Scored<IListItem>>
+        {
+            S("SF1", 100),
+            S("SF2", 60),
+        };
+
+        var apps = new List<Scored<IListItem>>
+        {
+            S("A1", 100),
+            S("A2", 55),
+        };
+
+        // Fallbacks are not scored.
+        var fallbacks = new List<Scored<IListItem>>
+        {
+            S("FB1", 0),
+            S("FB2", 0),
+        };
+
+        var result = MainListPageResultFactory.Create(
+            filtered,
+            scoredFallback,
+            apps,
+            fallbacks,
+            appResultLimit: 10);
+
+        // Expected order:
+        // 100: F1, SF1, A1
+        // 60: SF2
+        // 55: A2
+        // 50: F2
+        // Then fallbacks in original order: FB1, FB2
+        var titles = result.Select(r => r.Title).ToArray();
+#pragma warning disable CA1861 // Avoid constant arrays as arguments
+        CollectionAssert.AreEqual(
+            new[] { "F1", "SF1", "A1", "SF2", "A2", "F2", "FB1", "FB2" },
+            titles);
+#pragma warning restore CA1861 // Avoid constant arrays as arguments
+    }
+
+    [TestMethod]
+    public void Merge_AppliesAppLimit()
+    {
+        var apps = new List<Scored<IListItem>>
+        {
+            S("A1", 100),
+            S("A2", 90),
+            S("A3", 80),
+        };
+
+        var result = MainListPageResultFactory.Create(
+            null,
+            null,
+            apps,
+            null,
+            2);
+
+        Assert.AreEqual(2, result.Length);
+        Assert.AreEqual("A1", result[0].Title);
+        Assert.AreEqual("A2", result[1].Title);
+    }
+
+    [TestMethod]
+    public void Merge_FiltersEmptyFallbacks()
+    {
+        var fallbacks = new List<Scored<IListItem>>
+        {
+            S("FB1", 0),
+            S(string.Empty, 0),
+            S("FB3", 0),
+        };
+
+        var result = MainListPageResultFactory.Create(
+            null,
+            null,
+            null,
+            fallbacks,
+            appResultLimit: 10);
+
+        Assert.AreEqual(2, result.Length);
+        Assert.AreEqual("FB1", result[0].Title);
+        Assert.AreEqual("FB3", result[1].Title);
+    }
+
+    [TestMethod]
+    public void Merge_HandlesNullLists()
+    {
+        var result = MainListPageResultFactory.Create(
+            null,
+            null,
+            null,
+            null,
+            appResultLimit: 10);
+
+        Assert.IsNotNull(result);
+        Assert.AreEqual(0, result.Length);
+    }
+}

src/modules/cmdpal/ext/SamplePagesExtension/Pages/SampleListPageWithDetails.cs

@@ -5,7 +5,6 @@
 using System;
 using Microsoft.CommandPalette.Extensions;
 using Microsoft.CommandPalette.Extensions.Toolkit;
-using Microsoft.UI.Xaml;
 
 namespace SamplePagesExtension;
 
@@ -23,14 +22,34 @@ internal sealed partial class SampleListPageWithDetails : ListPage
         return [
             new ListItem(new NoOpCommand())
             {
-                Title = "This page demonstrates Details on ListItems",
+                Title = "Details on ListItems (Small)",
                 Details = new Details()
                 {
-                    Title = "List Item 1",
+                    Title = "This item has default details size",
                     Body = "Each of these items can have a `Body` formatted with **Markdown**",
                 },
             },
             new ListItem(new NoOpCommand())
+            {
+                Title = "Details on ListItems (Medium)",
+                Details = new Details()
+                {
+                    Title = "This item has medium details size",
+                    Body = "Each of these items can have a `Body` formatted with **Markdown**",
+                    Size = ContentSize.Medium,
+                },
+            },
+            new ListItem(new NoOpCommand())
+            {
+                Title = "Details on ListItems (Large)",
+                Details = new Details()
+                {
+                    Title = "This item has large details size",
+                    Body = "Each of these items can have a `Body` formatted with **Markdown**",
+                    Size = ContentSize.Large,
+                },
+            },
+            new ListItem(new NoOpCommand())
             {
                 Title = "This one has a subtitle too",
                 Subtitle = "Example Subtitle",
@@ -70,11 +89,13 @@ internal sealed partial class SampleListPageWithDetails : ListPage
             new ListItem(new NoOpCommand())
             {
                 Title = "This one has metadata",
+                Subtitle = "And Large Details panel",
                 Tags = [],
                 Details = new Details()
                 {
                     Title = "Metadata Example",
                     Body = "Each of the sections below is some sample metadata",
+                    Size = ContentSize.Large,
                     Metadata = [
                         new DetailsElement()
                         {

src/modules/cmdpal/extensionsdk/Microsoft.CommandPalette.Extensions.Toolkit/Details.cs

@@ -1,10 +1,11 @@
 // Copyright (c) Microsoft Corporation
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
+using Windows.Foundation.Collections;
 
 namespace Microsoft.CommandPalette.Extensions.Toolkit;
 
-public partial class Details : BaseObservable, IDetails
+public partial class Details : BaseObservable, IDetails, IExtendedAttributesProvider
 {
     public virtual IIconInfo HeroImage
     {
@@ -53,4 +54,21 @@ public partial class Details : BaseObservable, IDetails
     }
 
 = [];
+
+    public virtual ContentSize Size
+    {
+        get;
+        set
+        {
+            field = value;
+            OnPropertyChanged(nameof(Size));
+        }
+    }
+
+= ContentSize.Small;
+
+    public IDictionary<string, object>? GetProperties() => new ValueSet()
+    {
+        { "Size", (int)Size },
+    };
 }

src/modules/cmdpal/extensionsdk/Microsoft.CommandPalette.Extensions/Microsoft.CommandPalette.Extensions.idl

@@ -160,6 +160,15 @@ namespace Microsoft.CommandPalette.Extensions
     [uuid("6a6dd345-37a3-4a1e-914d-4f658a4d583d")]
     [contract(Microsoft.CommandPalette.Extensions.ExtensionsContract, 1)]
     interface IDetailsData {}
+
+    [contract(Microsoft.CommandPalette.Extensions.ExtensionsContract, 1)]
+    enum ContentSize
+    {
+        Small = 0,
+        Medium = 1,
+        Large = 2,
+    };
+
     [contract(Microsoft.CommandPalette.Extensions.ExtensionsContract, 1)]
     interface IDetailsElement {
         String Key { get; };

src/modules/cmdpal/extensionsdk/Microsoft.CommandPalette.Extensions/Microsoft.CommandPalette.Extensions.vcxproj

@@ -4,7 +4,7 @@
     <PathToRoot>..\..\..\..\..\</PathToRoot>
     <WasdkNuget>$(PathToRoot)packages\Microsoft.WindowsAppSDK.1.8.250907003</WasdkNuget>
     <CppWinRTNuget>$(PathToRoot)packages\Microsoft.Windows.CppWinRT.2.0.240111.5</CppWinRTNuget>
-    <WindowsSdkBuildToolsNuget>$(PathToRoot)packages\Microsoft.Windows.SDK.BuildTools.10.0.26100.4188</WindowsSdkBuildToolsNuget>
+    <WindowsSdkBuildToolsNuget>$(PathToRoot)packages\Microsoft.Windows.SDK.BuildTools.10.0.26100.6901</WindowsSdkBuildToolsNuget>
     <WebView2Nuget>$(PathToRoot)packages\Microsoft.Web.WebView2.1.0.2903.40</WebView2Nuget>
   </PropertyGroup>
   <Import Project="$(WasdkNuget)\build\native\Microsoft.WindowsAppSDK.props" Condition="Exists('$(WasdkNuget)\build\native\Microsoft.WindowsAppSDK.props')" />

src/modules/cmdpal/extensionsdk/Microsoft.CommandPalette.Extensions/packages.config

@@ -12,6 +12,6 @@
   <package id="Microsoft.WindowsAppSDK.InteractiveExperiences" version="1.8.250906004" targetFramework="native" />
   <package id="Microsoft.WindowsAppSDK.Widgets" version="1.8.250904007" targetFramework="native" />
   <package id="Microsoft.WindowsAppSDK.AI" version="1.8.37" targetFramework="native" />
-  <package id="Microsoft.Windows.SDK.BuildTools" version="10.0.26100.4188" targetFramework="native" />
+  <package id="Microsoft.Windows.SDK.BuildTools" version="10.0.26100.6901" targetFramework="native" />
   <package id="Microsoft.Windows.SDK.BuildTools.MSIX" version="1.7.20250829.1" targetFramework="native" />
-</packages>
+</packages>

src/modules/cmdpal/extensionsdk/nuget/BuildSDKHelper.ps1

@@ -54,9 +54,15 @@ if ($IsAzurePipelineBuild) {
 } else {
   $nugetPath = (Join-Path $PSScriptRoot "NugetWrapper.cmd")
 }
+$solutionPath = (Join-Path $PSScriptRoot "..\..\..\..\..\PowerToys.slnx")
 
 if (($BuildStep -ieq "all") -Or ($BuildStep -ieq "build")) {
-  & $nugetPath restore (Join-Path $PSScriptRoot "..\..\..\..\..\PowerToys.slnx")
+  $restoreArgs = @(
+    $solutionPath
+    "/t:Restore"
+    "/p:RestorePackagesConfig=true"
+  )
+  & $msbuildPath $restoreArgs
 
   Try {
     foreach ($config in $Configuration.Split(",")) {

src/modules/fancyzones/FancyZones.UITests/DragWindowTests.cs

@@ -4,6 +4,7 @@
 
 using System;
 using System.Collections.Generic;
+using System.Threading;
 using System.Threading.Tasks;
 using System.Windows.Forms;
 using FancyZonesEditor.Models;
@@ -49,19 +50,16 @@ namespace UITests_FancyZones
         [TestInitialize]
         public void TestInitialize()
         {
-            // ClearOpenWindows
+            Session.KillAllProcessesByName("PowerToys");
             ClearOpenWindows();
 
-            // kill all processes related to FancyZones Editor to ensure a clean state
-            Session.KillAllProcessesByName("PowerToys.FancyZonesEditor");
-
             AppZoneHistory.DeleteFile();
-            this.RestartScopeExe();
             FancyZonesEditorHelper.Files.Restore();
-
-            // Set a custom layout with 1 subzones and clear app zone history
             SetupCustomLayouts();
 
+            RestartScopeExe("Hosts");
+            Thread.Sleep(2000);
+
             // Get the current mouse button setting
             nonPrimaryMouseButton = SystemInformation.MouseButtonsSwapped ? "Left" : "Right";
 
@@ -72,99 +70,6 @@ namespace UITests_FancyZones
             LaunchFancyZones();
         }
 
-        /// <summary>
-        /// Test Use Shift key to activate zones while dragging a window in FancyZones Zone Behaviour Settings
-        /// <list type="bullet">
-        /// <item>
-        /// <description>Verifies that holding Shift while dragging shows all zones as expected.</description>
-        /// </item>
-        /// </list>
-        /// </summary>
-        [TestMethod("FancyZones.Settings.TestShowZonesOnShiftDuringDrag")]
-        [TestCategory("FancyZones_Dragging #1")]
-        public void TestShowZonesOnShiftDuringDrag()
-        {
-            string testCaseName = nameof(TestShowZonesOnShiftDuringDrag);
-            Pane dragElement = Find<Pane>(By.Name("Non Client Input Sink Window")); // element to drag
-            var offSet = ZoneSwitchHelper.GetOffset(dragElement, quarterX, quarterY);
-
-            var (initialColor, withShiftColor) = RunDragInteractions(
-              preAction: () =>
-              {
-                  dragElement.DragAndHold(offSet.Dx, offSet.Dy);
-              },
-              postAction: () =>
-              {
-                  Session.PressKey(Key.Shift);
-                  Task.Delay(500).Wait();
-              },
-              releaseAction: () =>
-              {
-                  Session.ReleaseKey(Key.Shift);
-                  Task.Delay(5000).Wait(); // Optional: Wait for a moment to ensure window switch
-              },
-              testCaseName: testCaseName);
-
-            string zoneColorWithoutShift = GetOutWindowPixelColor(30);
-
-            Assert.AreNotEqual(initialColor, withShiftColor, $"[{testCaseName}] Zone display failed.");
-            Assert.IsTrue(
-    withShiftColor == inactivateColor || withShiftColor == highlightColor,
-    $"[{testCaseName}] Zone display failed: withShiftColor was {withShiftColor}, expected {inactivateColor} or {highlightColor}.");
-            Assert.AreEqual(inactivateColor, withShiftColor, $"[{testCaseName}] Zone display failed.");
-
-            Assert.AreEqual(zoneColorWithoutShift, initialColor, $"[{testCaseName}] Zone deactivated failed.");
-            dragElement.ReleaseDrag();
-
-            Clean();
-        }
-
-        /// <summary>
-        /// Test dragging a window during Shift key press in FancyZones Zone Behaviour Settings
-        /// <list type="bullet">
-        /// <item>
-        /// <description>Verifies that dragging activates zones as expected.</description>
-        /// </item>
-        /// </list>
-        /// </summary>
-        [TestMethod("FancyZones.Settings.TestShowZonesOnDragDuringShift")]
-        [TestCategory("FancyZones_Dragging #2")]
-        public void TestShowZonesOnDragDuringShift()
-        {
-            string testCaseName = nameof(TestShowZonesOnDragDuringShift);
-
-            var dragElement = Find<Pane>(By.Name("Non Client Input Sink Window"));
-            var offSet = ZoneSwitchHelper.GetOffset(dragElement, quarterX, quarterY);
-
-            var (initialColor, withDragColor) = RunDragInteractions(
-                preAction: () =>
-                {
-                    dragElement.Drag(offSet.Dx, offSet.Dy);
-                    Session.PressKey(Key.Shift);
-                },
-                postAction: () =>
-                {
-                    dragElement.DragAndHold(0, 0);
-                    Task.Delay(5000).Wait();
-                },
-                releaseAction: () =>
-                {
-                    dragElement.ReleaseDrag();
-                    Session.ReleaseKey(Key.Shift);
-                },
-                testCaseName: testCaseName);
-
-            Assert.AreNotEqual(initialColor, withDragColor, $"[{testCaseName}] Zone color did not change; zone activation failed.");
-            Assert.AreEqual(highlightColor, withDragColor, $"[{testCaseName}] Zone color did not match the highlight color; activation failed.");
-
-            // double check by app-zone-history.json
-            string appZoneHistoryJson = AppZoneHistory.GetData();
-            string? zoneNumber = ZoneSwitchHelper.GetZoneIndexSetByAppName(powertoysWindowName, appZoneHistoryJson);
-            Assert.IsNull(zoneNumber, $"[{testCaseName}] AppZoneHistory layout was unexpectedly set.");
-
-            Clean();
-        }
-
         /// <summary>
         /// Test toggling zones using a non-primary mouse click during window dragging.
         /// <list type="bullet">
@@ -178,14 +83,19 @@ namespace UITests_FancyZones
         public void TestToggleZonesWithNonPrimaryMouseClick()
         {
             string testCaseName = nameof(TestToggleZonesWithNonPrimaryMouseClick);
-            var dragElement = Find<Pane>(By.Name("Non Client Input Sink Window"));
-            var offSet = ZoneSwitchHelper.GetOffset(dragElement, quarterX, quarterY);
+
+            var windowRect = Session.GetMainWindowRect();
+            int startX = windowRect.Left + 70;
+            int startY = windowRect.Top + 25;
+            int endX = startX + 300;
+            int endY = startY + 300;
 
             var (initialColor, withMouseColor) = RunDragInteractions(
                 preAction: () =>
                 {
-                    // activate zone
-                    dragElement.DragAndHold(offSet.Dx, offSet.Dy);
+                    Session.MoveMouseTo(startX, startY);
+                    Session.PerformMouseAction(MouseActionType.LeftDown);
+                    Session.MoveMouseTo(endX, endY);
                 },
                 postAction: () =>
                 {
@@ -195,7 +105,7 @@ namespace UITests_FancyZones
                 },
                 releaseAction: () =>
                 {
-                    dragElement.ReleaseDrag();
+                    Session.PerformMouseAction(MouseActionType.LeftUp);
                 },
                 testCaseName: testCaseName);
 
@@ -204,8 +114,6 @@ namespace UITests_FancyZones
 
             // check the zone color is activated
             Assert.AreEqual(highlightColor, initialColor, $"[{testCaseName}] Zone activation failed.");
-
-            Clean();
         }
 
         /// <summary>
@@ -221,32 +129,35 @@ namespace UITests_FancyZones
         public void TestShowZonesWhenShiftAndMouseOff()
         {
             string testCaseName = nameof(TestShowZonesWhenShiftAndMouseOff);
-            Pane dragElement = Find<Pane>(By.Name("Non Client Input Sink Window"));
-            var offSet = ZoneSwitchHelper.GetOffset(dragElement, quarterX, quarterY);
+
+            var windowRect = Session.GetMainWindowRect();
+            int startX = windowRect.Left + 70;
+            int startY = windowRect.Top + 25;
+            int endX = startX + 300;
+            int endY = startY + 300;
 
             var (initialColor, withShiftColor) = RunDragInteractions(
                preAction: () =>
                {
-                   // activate zone
-                   dragElement.DragAndHold(offSet.Dx, offSet.Dy);
+                   Session.MoveMouseTo(startX, startY);
+                   Session.PerformMouseAction(MouseActionType.LeftDown);
+                   Session.MoveMouseTo(endX, endY);
                },
                postAction: () =>
                {
                    // press Shift Key to deactivate zones
                    Session.PressKey(Key.Shift);
-                   Task.Delay(500).Wait();
+                   Task.Delay(1000).Wait();
                },
                releaseAction: () =>
                {
-                   dragElement.ReleaseDrag();
+                   Session.PerformMouseAction(MouseActionType.LeftUp);
                    Session.ReleaseKey(Key.Shift);
                },
                testCaseName: testCaseName);
 
             Assert.AreEqual(highlightColor, initialColor, $"[{testCaseName}] Zone activation failed.");
             Assert.AreNotEqual(highlightColor, withShiftColor, $"[{testCaseName}] Zone deactivation failed.");
-
-            Clean();
         }
 
         /// <summary>
@@ -263,12 +174,17 @@ namespace UITests_FancyZones
         {
             string testCaseName = nameof(TestShowZonesWhenShiftAndMouseOn);
 
-            var dragElement = Find<Pane>(By.Name("Non Client Input Sink Window"));
-            var offSet = ZoneSwitchHelper.GetOffset(dragElement, quarterX, quarterY);
+            var windowRect = Session.GetMainWindowRect();
+            int startX = windowRect.Left + 70;
+            int startY = windowRect.Top + 25;
+            int endX = startX + 300;
+            int endY = startY + 300;
             var (initialColor, withShiftColor) = RunDragInteractions(
              preAction: () =>
              {
-                 dragElement.DragAndHold(offSet.Dx, offSet.Dy);
+                 Session.MoveMouseTo(startX, startY);
+                 Session.PerformMouseAction(MouseActionType.LeftDown);
+                 Session.MoveMouseTo(endX, endY);
              },
              postAction: () =>
              {
@@ -279,7 +195,7 @@ namespace UITests_FancyZones
              },
              testCaseName: testCaseName);
 
-            Assert.AreEqual(inactivateColor, withShiftColor, $"[{testCaseName}] show zone failed.");
+            Assert.AreEqual(highlightColor, withShiftColor, $"[{testCaseName}] show zone failed.");
 
             Session.PerformMouseAction(
              nonPrimaryMouseButton == "Right" ? MouseActionType.RightClick : MouseActionType.LeftClick);
@@ -288,9 +204,7 @@ namespace UITests_FancyZones
             Assert.AreEqual(initialColor, zoneColorWithMouse, $"[{nameof(TestShowZonesWhenShiftAndMouseOff)}] Zone deactivate failed.");
 
             Session.ReleaseKey(Key.Shift);
-            dragElement.ReleaseDrag();
-
-            Clean();
+            Session.PerformMouseAction(MouseActionType.LeftUp);
         }
 
         /// <summary>
@@ -307,8 +221,6 @@ namespace UITests_FancyZones
         {
             var pixel = GetPixelWhenMakeDraggedWindow();
             Assert.AreNotEqual(pixel.PixelInWindow, pixel.TransPixel, $"[{nameof(TestMakeDraggedWindowTransparentOn)}]  Window transparency failed.");
-
-            Clean();
         }
 
         /// <summary>
@@ -325,14 +237,103 @@ namespace UITests_FancyZones
         {
             var pixel = GetPixelWhenMakeDraggedWindow();
             Assert.AreEqual(pixel.PixelInWindow, pixel.TransPixel, $"[{nameof(TestMakeDraggedWindowTransparentOff)}]  Window without transparency failed.");
-
-            Clean();
         }
 
-        private void Clean()
+        /// <summary>
+        /// Test Use Shift key to activate zones while dragging a window in FancyZones Zone Behaviour Settings
+        /// <list type="bullet">
+        /// <item>
+        /// <description>Verifies that holding Shift while dragging shows all zones as expected.</description>
+        /// </item>
+        /// </list>
+        /// </summary>
+        [TestMethod("FancyZones.Settings.TestShowZonesOnShiftDuringDrag")]
+        [TestCategory("FancyZones_Dragging #1")]
+        public void TestShowZonesOnShiftDuringDrag()
         {
-            // clean app zone history file
-            AppZoneHistory.DeleteFile();
+            string testCaseName = nameof(TestShowZonesOnShiftDuringDrag);
+
+            var windowRect = Session.GetMainWindowRect();
+            int startX = windowRect.Left + 70;
+            int startY = windowRect.Top + 25;
+            int endX = startX + 300;
+            int endY = startY + 300;
+
+            var (initialColor, withShiftColor) = RunDragInteractions(
+              preAction: () =>
+              {
+                  Session.MoveMouseTo(startX, startY);
+                  Session.PerformMouseAction(MouseActionType.LeftDown);
+                  Session.MoveMouseTo(endX, endY);
+              },
+              postAction: () =>
+              {
+                  Session.PressKey(Key.Shift);
+                  Task.Delay(500).Wait();
+              },
+              releaseAction: () =>
+              {
+                  Session.ReleaseKey(Key.Shift);
+                  Task.Delay(1000).Wait(); // Optional: Wait for a moment to ensure window switch
+              },
+              testCaseName: testCaseName);
+
+            string zoneColorWithoutShift = GetOutWindowPixelColor(30);
+
+            Assert.AreNotEqual(initialColor, withShiftColor, $"[{testCaseName}] Zone color did not change; zone activation failed.");
+            Assert.AreEqual(highlightColor, withShiftColor, $"[{testCaseName}] Zone color did not match the highlight color; activation failed.");
+
+            Session.PerformMouseAction(MouseActionType.LeftUp);
+        }
+
+        /// <summary>
+        /// Test dragging a window during Shift key press in FancyZones Zone Behaviour Settings
+        /// <list type="bullet">
+        /// <item>
+        /// <description>Verifies that dragging activates zones as expected.</description>
+        /// </item>
+        /// </list>
+        /// </summary>
+        [TestMethod("FancyZones.Settings.TestShowZonesOnDragDuringShift")]
+        [TestCategory("FancyZones_Dragging #2")]
+        public void TestShowZonesOnDragDuringShift()
+        {
+            string testCaseName = nameof(TestShowZonesOnDragDuringShift);
+
+            var windowRect = Session.GetMainWindowRect();
+            int startX = windowRect.Left + 70;
+            int startY = windowRect.Top + 25;
+            int endX = startX + 300;
+            int endY = startY + 300;
+
+            var (initialColor, withDragColor) = RunDragInteractions(
+                preAction: () =>
+                {
+                    Session.PressKey(Key.Shift);
+                    Task.Delay(100).Wait();
+                },
+                postAction: () =>
+                {
+                    Session.MoveMouseTo(startX, startY);
+                    Session.PerformMouseAction(MouseActionType.LeftDown);
+                    Session.MoveMouseTo(endX, endY);
+                    Task.Delay(1000).Wait();
+                },
+                releaseAction: () =>
+                {
+                    Session.PerformMouseAction(MouseActionType.LeftUp);
+                    Session.ReleaseKey(Key.Shift);
+                    Task.Delay(100).Wait();
+                },
+                testCaseName: testCaseName);
+
+            Assert.AreNotEqual(initialColor, withDragColor, $"[{testCaseName}] Zone color did not change; zone activation failed.");
+            Assert.AreEqual(highlightColor, withDragColor, $"[{testCaseName}] Zone color did not match the highlight color; activation failed.");
+
+            // double check by app-zone-history.json
+            string appZoneHistoryJson = AppZoneHistory.GetData();
+            string? zoneNumber = ZoneSwitchHelper.GetZoneIndexSetByAppName(powertoysWindowName, appZoneHistoryJson);
+            Assert.IsNull(zoneNumber, $"[{testCaseName}] AppZoneHistory layout was unexpectedly set.");
         }
 
         // Helper method to ensure the desktop has no open windows by clicking the "Show Desktop" button
@@ -352,7 +353,7 @@ namespace UITests_FancyZones
                 desktopButtonName = "Show Desktop";
             }
 
-            this.Find<Microsoft.PowerToys.UITest.Button>(By.Name(desktopButtonName), 5000, true).Click(false, 500, 2000);
+            this.Find<Microsoft.PowerToys.UITest.Button>(By.Name(desktopButtonName), 5000, true).Click(false, 500, 1000);
         }
 
         // Setup custom layout with 1 subzones
@@ -382,6 +383,11 @@ namespace UITests_FancyZones
             this.Scroll(6, "Down"); // Pull the settings page up to make sure the settings are visible
             ZoneBehaviourSettings(TestContext.TestName);
 
+            // Go back and forth to make sure settings applied
+            this.Find<NavigationViewItem>("Workspaces").Click();
+            Task.Delay(200).Wait();
+            this.Find<NavigationViewItem>("FancyZones").Click();
+
             this.Find<Microsoft.PowerToys.UITest.Button>(By.AccessibilityId("LaunchLayoutEditorButton")).Click(false, 500, 10000);
             this.Session.Attach(PowerToysModule.FancyZone);
 
@@ -435,22 +441,26 @@ namespace UITests_FancyZones
         // Get the mouse color of the pixel when make dragged window
         private (string PixelInWindow, string TransPixel) GetPixelWhenMakeDraggedWindow()
         {
-            var dragElement = Find<Pane>(By.Name("Non Client Input Sink Window"));
+            var windowRect = Session.GetMainWindowRect();
+            int startX = windowRect.Left + 70;
+            int startY = windowRect.Top + 25;
+            int endX = startX + 100;
+            int endY = startY + 100;
 
-            // maximize the window to make sure get pixel color more accurate
-            dragElement.DoubleClick();
+            Session.MoveMouseTo(startX, startY);
 
-            var offSet = ZoneSwitchHelper.GetOffset(dragElement, quarterX, quarterY);
+            // Session.PerformMouseAction(MouseActionType.LeftDoubleClick);
             Session.PressKey(Key.Shift);
-            dragElement.DragAndHold(offSet.Dx, offSet.Dy);
-            Task.Delay(1000).Wait(); // Optional: Wait for a moment to ensure the window is in position
+            Session.PerformMouseAction(MouseActionType.LeftDown);
+            Session.MoveMouseTo(endX, endY);
+
             Tuple<int, int> pos = GetMousePosition();
             string pixelInWindow = this.GetPixelColorString(pos.Item1, pos.Item2);
             Session.ReleaseKey(Key.Shift);
-            Task.Delay(1000).Wait(); // Optional: Wait for a moment to ensure the window is in position
+            Task.Delay(1000).Wait();
             string transPixel = this.GetPixelColorString(pos.Item1, pos.Item2);
-            dragElement.ReleaseDrag();
 
+            Session.PerformMouseAction(MouseActionType.LeftUp);
             return (pixelInWindow, transPixel);
         }
 

src/modules/fancyzones/FancyZones.UITests/LayoutApplyHotKeyTests.cs

@@ -271,7 +271,7 @@ namespace UITests_FancyZones
             };
             FancyZonesEditorHelper.Files.AppliedLayoutsIOHelper.WriteData(appliedLayouts.Serialize(appliedLayoutsWrapper));
 
-            this.RestartScopeExe();
+            RestartScopeExe("Hosts");
         }
 
         [TestMethod("FancyZones.Settings.TestApplyHotKey")]
@@ -598,10 +598,12 @@ namespace UITests_FancyZones
             this.TryReaction();
             int tries = 24;
             Pull(tries, "down"); // Pull the setting page up to make sure the setting is visible
-            this.Find<ToggleSwitch>("Enable quick layout switch").Toggle(flag);
+            this.Find<ToggleSwitch>("FancyZonesQuickLayoutSwitch").Toggle(flag);
 
-            tries = 24;
-            Pull(tries, "up");
+            // Go back and forth to make sure settings applied
+            this.Find<NavigationViewItem>("Workspaces").Click();
+            Task.Delay(200).Wait();
+            this.Find<NavigationViewItem>("FancyZones").Click();
         }
 
         private void TryReaction()

src/modules/fancyzones/FancyZones.UITests/OneZoneSwitchTests.cs

@@ -34,7 +34,7 @@ namespace UITests_FancyZones
             Session.KillAllProcessesByName("PowerToys.FancyZonesEditor");
             AppZoneHistory.DeleteFile();
 
-            this.RestartScopeExe();
+            RestartScopeExe("Hosts");
             FancyZonesEditorHelper.Files.Restore();
 
             // Set a custom layout with 1 subzones and clear app zone history
@@ -137,7 +137,7 @@ namespace UITests_FancyZones
             Task.Delay(500).Wait(); // Optional: Wait for a moment to ensure window switch
 
             activeWindowTitle = ZoneSwitchHelper.GetActiveWindowTitle();
-            Assert.AreNotEqual(preWindow, activeWindowTitle);
+            Assert.AreEqual(postWindow, activeWindowTitle);
 
             Clean(); // close the windows
         }
@@ -151,9 +151,23 @@ namespace UITests_FancyZones
 
             var rect = Session.GetMainWindowRect();
             var (targetX, targetY) = ZoneSwitchHelper.GetScreenMargins(rect, 4);
-            var offSet = ZoneSwitchHelper.GetOffset(hostsView, targetX, targetY);
 
-            DragWithShift(hostsView, offSet);
+            // Snap first window (Hosts) to left zone using shift+drag with direct mouse movement
+            var hostsRect = hostsView.Rect ?? throw new InvalidOperationException("Failed to get hosts window rect");
+            int hostsStartX = hostsRect.Left + 70;
+            int hostsStartY = hostsRect.Top + 25;
+
+            // For a 2-column layout, left zone is at approximately 1/4 of screen width
+            int hostsEndX = rect.Left + (3 * (rect.Right - rect.Left) / 4);
+            int hostsEndY = rect.Top + ((rect.Bottom - rect.Top) / 2);
+
+            Session.MoveMouseTo(hostsStartX, hostsStartY);
+            Session.PerformMouseAction(MouseActionType.LeftDown);
+            Session.PressKey(Key.Shift);
+            Session.MoveMouseTo(hostsEndX, hostsEndY);
+            Session.PerformMouseAction(MouseActionType.LeftUp);
+            Session.ReleaseKey(Key.Shift);
+            Task.Delay(500).Wait(); // Wait for snap to complete
 
             string preWindow = ZoneSwitchHelper.GetActiveWindowTitle();
 
@@ -163,11 +177,26 @@ namespace UITests_FancyZones
             Pane settingsView = Find<Pane>(By.Name("Non Client Input Sink Window"));
             settingsView.DoubleClick(); // maximize the window
 
-            DragWithShift(settingsView, offSet);
+            var windowRect = Session.GetMainWindowRect();
+            var settingsRect = settingsView.Rect ?? throw new InvalidOperationException("Failed to get settings window rect");
+            int settingsStartX = settingsRect.Left + 70;
+            int settingsStartY = settingsRect.Top + 25;
+
+            // For a 2-column layout, right zone is at approximately 3/4 of screen width
+            int settingsEndX = windowRect.Left + (3 * (windowRect.Right - windowRect.Left) / 4);
+            int settingsEndY = windowRect.Top + ((windowRect.Bottom - windowRect.Top) / 2);
+
+            Session.MoveMouseTo(settingsStartX, settingsStartY);
+            Session.PerformMouseAction(MouseActionType.LeftDown);
+            Session.PressKey(Key.Shift);
+            Session.MoveMouseTo(settingsEndX, settingsEndY);
+            Session.PerformMouseAction(MouseActionType.LeftUp);
+            Session.ReleaseKey(Key.Shift);
+            Task.Delay(500).Wait(); // Wait for snap to complete
 
             string appZoneHistoryJson = AppZoneHistory.GetData();
 
-            string? zoneIndexOfFileWindow = ZoneSwitchHelper.GetZoneIndexSetByAppName("PowerToys.Hosts.exe", appZoneHistoryJson); // explorer.exe
+            string? zoneIndexOfFileWindow = ZoneSwitchHelper.GetZoneIndexSetByAppName("PowerToys.Hosts.exe", appZoneHistoryJson);
             string? zoneIndexOfPowertoys = ZoneSwitchHelper.GetZoneIndexSetByAppName("PowerToys.Settings.exe", appZoneHistoryJson);
 
             // check the AppZoneHistory layout is set and in the same zone
@@ -176,16 +205,6 @@ namespace UITests_FancyZones
             return (preWindow, powertoysWindowName);
         }
 
-        private void DragWithShift(Pane settingsView, (int Dx, int Dy) offSet)
-        {
-            Session.PressKey(Key.Shift);
-            settingsView.DragAndHold(offSet.Dx, offSet.Dy);
-            Task.Delay(1000).Wait(); // Wait for drag to start (optional)
-            settingsView.ReleaseDrag();
-            Task.Delay(1000).Wait(); // Wait after drag (optional)
-            Session.ReleaseKey(Key.Shift);
-        }
-
         private static readonly CustomLayouts.CustomLayoutListWrapper CustomLayoutsList = new CustomLayouts.CustomLayoutListWrapper
         {
             CustomLayouts = new List<CustomLayouts.CustomLayoutWrapper>
@@ -253,11 +272,14 @@ namespace UITests_FancyZones
             this.Scroll(9, "Down"); // Pull the setting page up to make sure the setting is visible
             bool switchWindowEnable = TestContext.TestName == "TestSwitchShortCutDisable" ? false : true;
 
-            this.Find<ToggleSwitch>("Switch between windows in the current zone").Toggle(switchWindowEnable);
+            this.Find<ToggleSwitch>("FancyZonesWindowSwitchingToggle").Toggle(switchWindowEnable);
 
-            Task.Delay(500).Wait(); // Wait for the setting to be applied
-            this.Scroll(9, "Up"); // Pull the setting page down to make sure the setting is visible
-            this.Find<Button>("Launch layout editor").Click(false, 500, 5000);
+            // Go back and forth to make sure settings applied
+            this.Find<NavigationViewItem>("Workspaces").Click();
+            Task.Delay(200).Wait();
+            this.Find<NavigationViewItem>("FancyZones").Click();
+
+            this.Find<Button>("Open layout editor").Click(false, 500, 5000);
             this.Session.Attach(PowerToysModule.FancyZone);
 
             // pipeline machine may have an unstable delays, causing the custom layout to be unavailable as we set. then A retry is required.
@@ -273,7 +295,7 @@ namespace UITests_FancyZones
                 this.Find<Microsoft.PowerToys.UITest.Button>("Close").Click();
                 this.Session.Attach(PowerToysModule.PowerToysSettings);
                 SetupCustomLayouts();
-                this.Find<Microsoft.PowerToys.UITest.Button>("Launch layout editor").Click(false, 5000, 5000);
+                this.Find<Microsoft.PowerToys.UITest.Button>("Open layout editor").Click(false, 5000, 5000);
                 this.Session.Attach(PowerToysModule.FancyZone);
 
                 // customLayoutData = FancyZonesEditorHelper.Files.CustomLayoutsIOHelper.GetData();
@@ -301,11 +323,11 @@ namespace UITests_FancyZones
             Task.Delay(1000).Wait();
 
             this.Find<ToggleSwitch>("Enable Hosts File Editor").Toggle(true);
-            this.Find<ToggleSwitch>("Launch as administrator").Toggle(launchAsAdmin);
+            this.Find<ToggleSwitch>("Open as administrator").Toggle(launchAsAdmin);
             this.Find<ToggleSwitch>("Show a warning at startup").Toggle(showWarning);
 
             // launch Hosts File Editor
-            this.Find<Button>("Launch Hosts File Editor").Click();
+            this.Find<Button>("Open Hosts File Editor").Click();
 
             Task.Delay(5000).Wait();
         }

src/modules/fancyzones/FancyZonesCLI/Commands/EditorCommands.cs

@@ -0,0 +1,90 @@
+// Copyright (c) Microsoft Corporation
+// The Microsoft Corporation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System;
+using System.Diagnostics;
+using System.IO;
+using System.Linq;
+
+namespace FancyZonesCLI.Commands;
+
+/// <summary>
+/// Editor and Settings commands.
+/// </summary>
+internal static class EditorCommands
+{
+    public static (int ExitCode, string Output) OpenEditor()
+    {
+        var editorExe = "PowerToys.FancyZonesEditor.exe";
+
+        // Check if editor-parameters.json exists
+        if (!FancyZonesData.EditorParametersExist())
+        {
+            return (1, "Error: editor-parameters.json not found.\nPlease launch FancyZones Editor using Win+` (Win+Backtick) hotkey first.");
+        }
+
+        // Check if editor is already running
+        var existingProcess = Process.GetProcessesByName("PowerToys.FancyZonesEditor").FirstOrDefault();
+        if (existingProcess != null)
+        {
+            NativeMethods.SetForegroundWindow(existingProcess.MainWindowHandle);
+            return (0, "FancyZones Editor is already running. Brought window to foreground.");
+        }
+
+        // Only check same directory as CLI
+        var editorPath = Path.Combine(AppContext.BaseDirectory, editorExe);
+
+        if (File.Exists(editorPath))
+        {
+            try
+            {
+                Process.Start(new ProcessStartInfo
+                {
+                    FileName = editorPath,
+                    UseShellExecute = true,
+                });
+                return (0, "FancyZones Editor launched successfully.");
+            }
+            catch (Exception ex)
+            {
+                return (1, $"Failed to launch: {ex.Message}");
+            }
+        }
+
+        return (1, $"Error: Could not find {editorExe} in {AppContext.BaseDirectory}");
+    }
+
+    public static (int ExitCode, string Output) OpenSettings()
+    {
+        try
+        {
+            // Find PowerToys.exe in common locations
+            string powertoysExe = null;
+
+            // Check in the same directory as the CLI (typical for dev builds)
+            var sameDirPath = Path.Combine(AppContext.BaseDirectory, "PowerToys.exe");
+            if (File.Exists(sameDirPath))
+            {
+                powertoysExe = sameDirPath;
+            }
+
+            if (powertoysExe == null)
+            {
+                return (1, "Error: PowerToys.exe not found. Please ensure PowerToys is installed.");
+            }
+
+            Process.Start(new ProcessStartInfo
+            {
+                FileName = powertoysExe,
+                Arguments = "--open-settings=FancyZones",
+                UseShellExecute = false,
+            });
+            return (0, "FancyZones Settings opened successfully.");
+        }
+        catch (Exception ex)
+        {
+            return (1, $"Error: Failed to open FancyZones Settings. {ex.Message}");
+        }
+    }
+}

src/modules/fancyzones/FancyZonesCLI/Commands/HotkeyCommands.cs

@@ -0,0 +1,98 @@
+// Copyright (c) Microsoft Corporation
+// The Microsoft Corporation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System;
+using System.Collections.Generic;
+using System.Globalization;
+using System.Linq;
+
+namespace FancyZonesCLI.Commands;
+
+/// <summary>
+/// Hotkey-related commands.
+/// </summary>
+internal static class HotkeyCommands
+{
+    public static (int ExitCode, string Output) GetHotkeys()
+    {
+        var hotkeys = FancyZonesData.ReadLayoutHotkeys();
+        if (hotkeys?.Hotkeys == null || hotkeys.Hotkeys.Count == 0)
+        {
+            return (0, "No hotkeys configured.");
+        }
+
+        var sb = new System.Text.StringBuilder();
+        sb.AppendLine("=== Layout Hotkeys ===\n");
+        sb.AppendLine("Press Win + Ctrl + Alt + <number> to switch layouts:\n");
+
+        foreach (var hotkey in hotkeys.Hotkeys.OrderBy(h => h.Key))
+        {
+            sb.AppendLine(CultureInfo.InvariantCulture, $"  [{hotkey.Key}] => {hotkey.LayoutId}");
+        }
+
+        return (0, sb.ToString().TrimEnd());
+    }
+
+    public static (int ExitCode, string Output) SetHotkey(int key, string layoutUuid, Action<uint> notifyFancyZones, uint wmPrivLayoutHotkeysFileUpdate)
+    {
+        if (key < 0 || key > 9)
+        {
+            return (1, "Error: Key must be between 0 and 9");
+        }
+
+        // Check if this is a custom layout UUID
+        var customLayouts = FancyZonesData.ReadCustomLayouts();
+        var matchedLayout = customLayouts?.Layouts?.FirstOrDefault(l => l.Uuid.Equals(layoutUuid, StringComparison.OrdinalIgnoreCase));
+        bool isCustomLayout = matchedLayout != null;
+        string layoutName = matchedLayout?.Name ?? layoutUuid;
+
+        var hotkeys = FancyZonesData.ReadLayoutHotkeys() ?? new LayoutHotkeys();
+
+        hotkeys.Hotkeys ??= new List<LayoutHotkey>();
+
+        // Remove existing hotkey for this key
+        hotkeys.Hotkeys.RemoveAll(h => h.Key == key);
+
+        // Add new hotkey
+        hotkeys.Hotkeys.Add(new LayoutHotkey { Key = key, LayoutId = layoutUuid });
+
+        // Save
+        FancyZonesData.WriteLayoutHotkeys(hotkeys);
+
+        // Notify FancyZones
+        notifyFancyZones(wmPrivLayoutHotkeysFileUpdate);
+
+        if (isCustomLayout)
+        {
+            return (0, $"✓ Hotkey {key} assigned to custom layout '{layoutName}'\n  Press Win + Ctrl + Alt + {key} to switch to this layout");
+        }
+        else
+        {
+            return (0, $"⚠ Warning: Hotkey {key} assigned to '{layoutUuid}'\n  Note: FancyZones hotkeys only work with CUSTOM layouts.\n  Template layouts (focus, columns, rows, etc.) cannot be used with hotkeys.\n  Create a custom layout in the FancyZones Editor to use this hotkey.");
+        }
+    }
+
+    public static (int ExitCode, string Output) RemoveHotkey(int key, Action<uint> notifyFancyZones, uint wmPrivLayoutHotkeysFileUpdate)
+    {
+        var hotkeys = FancyZonesData.ReadLayoutHotkeys();
+        if (hotkeys?.Hotkeys == null)
+        {
+            return (0, $"No hotkey assigned to key {key}");
+        }
+
+        var removed = hotkeys.Hotkeys.RemoveAll(h => h.Key == key);
+        if (removed == 0)
+        {
+            return (0, $"No hotkey assigned to key {key}");
+        }
+
+        // Save
+        FancyZonesData.WriteLayoutHotkeys(hotkeys);
+
+        // Notify FancyZones
+        notifyFancyZones(wmPrivLayoutHotkeysFileUpdate);
+
+        return (0, $"Hotkey {key} removed");
+    }
+}

src/modules/fancyzones/FancyZonesCLI/Commands/LayoutCommands.cs

@@ -0,0 +1,276 @@
+// Copyright (c) Microsoft Corporation
+// The Microsoft Corporation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System;
+using System.Collections.Generic;
+using System.Globalization;
+using System.Linq;
+using System.Text.Json;
+
+namespace FancyZonesCLI.Commands;
+
+/// <summary>
+/// Layout-related commands.
+/// </summary>
+internal static class LayoutCommands
+{
+    public static (int ExitCode, string Output) GetLayouts()
+    {
+        var sb = new System.Text.StringBuilder();
+
+        // Print template layouts
+        var templatesJson = FancyZonesData.ReadLayoutTemplates();
+        if (templatesJson?.Templates != null)
+        {
+            sb.AppendLine(CultureInfo.InvariantCulture, $"=== Built-in Template Layouts ({templatesJson.Templates.Count} total) ===\n");
+
+            for (int i = 0; i < templatesJson.Templates.Count; i++)
+            {
+                var template = templatesJson.Templates[i];
+                sb.AppendLine(CultureInfo.InvariantCulture, $"[T{i + 1}] {template.Type}");
+                sb.Append(CultureInfo.InvariantCulture, $"    Zones: {template.ZoneCount}");
+                if (template.ShowSpacing && template.Spacing > 0)
+                {
+                    sb.Append(CultureInfo.InvariantCulture, $", Spacing: {template.Spacing}px");
+                }
+
+                sb.AppendLine();
+                sb.AppendLine();
+
+                // Draw visual preview
+                sb.Append(LayoutVisualizer.DrawTemplateLayout(template));
+
+                if (i < templatesJson.Templates.Count - 1)
+                {
+                    sb.AppendLine();
+                }
+            }
+
+            sb.AppendLine("\n");
+        }
+
+        // Print custom layouts
+        var customLayouts = FancyZonesData.ReadCustomLayouts();
+        if (customLayouts?.Layouts != null)
+        {
+            sb.AppendLine(CultureInfo.InvariantCulture, $"=== Custom Layouts ({customLayouts.Layouts.Count} total) ===");
+
+            for (int i = 0; i < customLayouts.Layouts.Count; i++)
+            {
+                var layout = customLayouts.Layouts[i];
+                sb.AppendLine(CultureInfo.InvariantCulture, $"[{i + 1}] {layout.Name}");
+                sb.AppendLine(CultureInfo.InvariantCulture, $"    UUID: {layout.Uuid}");
+                sb.Append(CultureInfo.InvariantCulture, $"    Type: {layout.Type}");
+
+                bool isCanvasLayout = false;
+                if (layout.Info.ValueKind != JsonValueKind.Undefined && layout.Info.ValueKind != JsonValueKind.Null)
+                {
+                    if (layout.Type == "grid" && layout.Info.TryGetProperty("rows", out var rows) && layout.Info.TryGetProperty("columns", out var cols))
+                    {
+                        sb.Append(CultureInfo.InvariantCulture, $" ({rows.GetInt32()}x{cols.GetInt32()} grid)");
+                    }
+                    else if (layout.Type == "canvas" && layout.Info.TryGetProperty("zones", out var zones))
+                    {
+                        sb.Append(CultureInfo.InvariantCulture, $" ({zones.GetArrayLength()} zones)");
+                        isCanvasLayout = true;
+                    }
+                }
+
+                sb.AppendLine("\n");
+
+                // Draw visual preview
+                sb.Append(LayoutVisualizer.DrawCustomLayout(layout));
+
+                // Add note for canvas layouts
+                if (isCanvasLayout)
+                {
+                    sb.AppendLine("\n    Note: Canvas layout preview is approximate.");
+                    sb.AppendLine("          Open FancyZones Editor for precise zone boundaries.");
+                }
+
+                if (i < customLayouts.Layouts.Count - 1)
+                {
+                    sb.AppendLine();
+                }
+            }
+
+            sb.AppendLine("\nUse 'FancyZonesCLI.exe set-layout <UUID>' to apply a layout.");
+        }
+
+        return (0, sb.ToString().TrimEnd());
+    }
+
+    public static (int ExitCode, string Output) GetActiveLayout()
+    {
+        if (!FancyZonesData.TryReadAppliedLayouts(out var appliedLayouts, out var error))
+        {
+            return (1, $"Error: {error}");
+        }
+
+        if (appliedLayouts.Layouts == null || appliedLayouts.Layouts.Count == 0)
+        {
+            return (0, "No active layouts found.");
+        }
+
+        var sb = new System.Text.StringBuilder();
+        sb.AppendLine("\n=== Active FancyZones Layout(s) ===\n");
+
+        for (int i = 0; i < appliedLayouts.Layouts.Count; i++)
+        {
+            var layout = appliedLayouts.Layouts[i];
+            sb.AppendLine(CultureInfo.InvariantCulture, $"Monitor {i + 1}:");
+            sb.AppendLine(CultureInfo.InvariantCulture, $"  Name: {layout.AppliedLayout.Type}");
+            sb.AppendLine(CultureInfo.InvariantCulture, $"  UUID: {layout.AppliedLayout.Uuid}");
+            sb.AppendLine(CultureInfo.InvariantCulture, $"  Type: {layout.AppliedLayout.Type} ({layout.AppliedLayout.ZoneCount} zones)");
+
+            if (layout.AppliedLayout.ShowSpacing)
+            {
+                sb.AppendLine(CultureInfo.InvariantCulture, $"  Spacing: {layout.AppliedLayout.Spacing}px");
+            }
+
+            sb.AppendLine(CultureInfo.InvariantCulture, $"  Sensitivity Radius: {layout.AppliedLayout.SensitivityRadius}px");
+
+            if (i < appliedLayouts.Layouts.Count - 1)
+            {
+                sb.AppendLine();
+            }
+        }
+
+        return (0, sb.ToString().TrimEnd());
+    }
+
+    public static (int ExitCode, string Output) SetLayout(string[] args, Action<uint> notifyFancyZones, uint wmPrivAppliedLayoutsFileUpdate)
+    {
+        Logger.LogInfo($"SetLayout called with args: [{string.Join(", ", args)}]");
+
+        if (args.Length == 0)
+        {
+            return (1, "Error: set-layout requires a UUID parameter");
+        }
+
+        string uuid = args[0];
+        int? targetMonitor = null;
+        bool applyToAll = false;
+
+        // Parse options
+        for (int i = 1; i < args.Length; i++)
+        {
+            if (args[i] == "--monitor" && i + 1 < args.Length)
+            {
+                if (int.TryParse(args[i + 1], out int monitorNum))
+                {
+                    targetMonitor = monitorNum;
+                    i++; // Skip next arg
+                }
+                else
+                {
+                    return (1, $"Error: Invalid monitor number: {args[i + 1]}");
+                }
+            }
+            else if (args[i] == "--all")
+            {
+                applyToAll = true;
+            }
+        }
+
+        if (targetMonitor.HasValue && applyToAll)
+        {
+            return (1, "Error: Cannot specify both --monitor and --all");
+        }
+
+        // Try to find layout in custom layouts first (by UUID)
+        var customLayouts = FancyZonesData.ReadCustomLayouts();
+        var targetCustomLayout = customLayouts?.Layouts?.FirstOrDefault(l => l.Uuid.Equals(uuid, StringComparison.OrdinalIgnoreCase));
+
+        // If not found in custom layouts, try template layouts (by type name)
+        TemplateLayout targetTemplate = null;
+        if (targetCustomLayout == null)
+        {
+            var templates = FancyZonesData.ReadLayoutTemplates();
+            targetTemplate = templates?.Templates?.FirstOrDefault(t => t.Type.Equals(uuid, StringComparison.OrdinalIgnoreCase));
+        }
+
+        if (targetCustomLayout == null && targetTemplate == null)
+        {
+            return (1, $"Error: Layout '{uuid}' not found\nTip: For templates, use the type name (e.g., 'focus', 'columns', 'rows', 'grid', 'priority-grid')\n     For custom layouts, use the UUID from 'get-layouts'");
+        }
+
+        // Read current applied layouts
+        if (!FancyZonesData.TryReadAppliedLayouts(out var appliedLayouts, out var error))
+        {
+            return (1, $"Error: {error}");
+        }
+
+        if (appliedLayouts.Layouts == null || appliedLayouts.Layouts.Count == 0)
+        {
+            return (1, "Error: No monitors configured");
+        }
+
+        // Determine which monitors to update
+        List<int> monitorsToUpdate = new List<int>();
+        if (applyToAll)
+        {
+            for (int i = 0; i < appliedLayouts.Layouts.Count; i++)
+            {
+                monitorsToUpdate.Add(i);
+            }
+        }
+        else if (targetMonitor.HasValue)
+        {
+            int monitorIndex = targetMonitor.Value - 1; // Convert to 0-based
+            if (monitorIndex < 0 || monitorIndex >= appliedLayouts.Layouts.Count)
+            {
+                return (1, $"Error: Monitor {targetMonitor.Value} not found. Available monitors: 1-{appliedLayouts.Layouts.Count}");
+            }
+
+            monitorsToUpdate.Add(monitorIndex);
+        }
+        else
+        {
+            // Default: first monitor
+            monitorsToUpdate.Add(0);
+        }
+
+        // Update selected monitors
+        foreach (int monitorIndex in monitorsToUpdate)
+        {
+            if (targetCustomLayout != null)
+            {
+                appliedLayouts.Layouts[monitorIndex].AppliedLayout.Uuid = targetCustomLayout.Uuid;
+                appliedLayouts.Layouts[monitorIndex].AppliedLayout.Type = targetCustomLayout.Type;
+            }
+            else if (targetTemplate != null)
+            {
+                // For templates, use all-zeros UUID and the template type
+                appliedLayouts.Layouts[monitorIndex].AppliedLayout.Uuid = "{00000000-0000-0000-0000-000000000000}";
+                appliedLayouts.Layouts[monitorIndex].AppliedLayout.Type = targetTemplate.Type;
+                appliedLayouts.Layouts[monitorIndex].AppliedLayout.ZoneCount = targetTemplate.ZoneCount;
+                appliedLayouts.Layouts[monitorIndex].AppliedLayout.ShowSpacing = targetTemplate.ShowSpacing;
+                appliedLayouts.Layouts[monitorIndex].AppliedLayout.Spacing = targetTemplate.Spacing;
+            }
+        }
+
+        // Write back to file
+        FancyZonesData.WriteAppliedLayouts(appliedLayouts);
+        Logger.LogInfo($"Applied layouts file updated for {monitorsToUpdate.Count} monitor(s)");
+
+        // Notify FancyZones to reload
+        notifyFancyZones(wmPrivAppliedLayoutsFileUpdate);
+        Logger.LogInfo("FancyZones notified of layout change");
+
+        string layoutName = targetCustomLayout?.Name ?? targetTemplate?.Type ?? uuid;
+        if (applyToAll)
+        {
+            return (0, $"Layout '{layoutName}' applied to all {monitorsToUpdate.Count} monitors");
+        }
+        else if (targetMonitor.HasValue)
+        {
+            return (0, $"Layout '{layoutName}' applied to monitor {targetMonitor.Value}");
+        }
+        else
+        {
+            return (0, $"Layout '{layoutName}' applied to monitor 1");
+        }
+    }
+}