CmdPal: Transparent window (#45159)

## Summary

This PR adds:
- Backdrop material customization
  - Alongside acrylic, the following options are now available:
  - Transparent background
  - Mica background
- Background material opacity
  - Lets you control how transparent the background is

## Pictures? Pictures!

<img width="1491" height="928" alt="image"
src="https://github.com/user-attachments/assets/ff4e9e06-fcf1-4f05-bc0a-fb70dc4f39be"
/>



https://github.com/user-attachments/assets/84e83279-afab-481e-b904-f054318c5d2f

<img width="977" height="628" alt="image"
src="https://github.com/user-attachments/assets/241a228d-af3f-448a-94a6-0a282218bd8c"
/>


## PR Checklist

- [x] Closes: #44197
<!-- - [ ] Closes: #yyy (add separate lines for additional resolved
issues) -->
- [ ] **Communication:** I've discussed this with core contributors
already. If the work hasn't been agreed, this work might be rejected
- [ ] **Tests:** Added/updated and all pass
- [ ] **Localization:** All end-user-facing strings can be localized
- [ ] **Dev docs:** Added/updated
- [ ] **New binaries:** Added on the required places
- [ ] [JSON for
signing](https://github.com/microsoft/PowerToys/blob/main/.pipelines/ESRPSigning_core.json)
for new binaries
- [ ] [WXS for
installer](https://github.com/microsoft/PowerToys/blob/main/installer/PowerToysSetup/Product.wxs)
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pipeline](https://github.com/microsoft/PowerToys/blob/main/.pipelines/ci/templates/build-powertoys-steps.yml)
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- [ ] **Documentation updated:** If checked, please file a pull request
on [our docs
repo](https://github.com/MicrosoftDocs/windows-uwp/tree/docs/hub/powertoys)
and link it here: #xxx

<!-- Provide a more detailed description of the PR, other things fixed,
or any additional comments/features here -->
## Detailed Description of the Pull Request / Additional comments

<!-- Describe how you validated the behavior. Add automated tests
wherever possible, but list manual validation steps taken as well -->
## Validation Steps Performed

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

@@ -288,7 +288,6 @@ internal sealed partial class BlurImageControl : Control
         _effectBrush?.Dispose();
         _effectBrush = effectFactory.CreateBrush();
 
-        // Set initial source
         if (ImageSource is not null)
         {
             _imageBrush ??= _compositor.CreateSurfaceBrush();

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

@@ -16,24 +16,38 @@
         CornerRadius="8"
         Translation="0,0,8">
         <Grid>
+            <!--  Clear style: SolidColorBrush with computed alpha (window backdrop)  -->
             <Border
                 HorizontalAlignment="Stretch"
                 VerticalAlignment="Stretch"
                 BorderBrush="{ThemeResource SurfaceStrokeColorDefaultBrush}"
                 BorderThickness="1"
-                Visibility="{x:Bind h:BindTransformers.NegateVisibility(ShowBackgroundImage), Mode=OneWay}">
+                Visibility="{x:Bind ClearVisibility, Mode=OneWay}">
+                <Border.Background>
+                    <SolidColorBrush Color="{x:Bind EffectiveClearColor, Mode=OneWay}" />
+                </Border.Background>
+            </Border>
+            <!--  Acrylic/Mica style: AcrylicBrush with effective opacity (window backdrop)  -->
+            <Border
+                HorizontalAlignment="Stretch"
+                VerticalAlignment="Stretch"
+                BorderBrush="{ThemeResource SurfaceStrokeColorDefaultBrush}"
+                BorderThickness="1"
+                Visibility="{x:Bind AcrylicVisibility, Mode=OneWay}">
                 <Border.Background>
                     <AcrylicBrush
                         FallbackColor="{x:Bind PreviewBackgroundColor, Mode=OneWay}"
                         TintColor="{x:Bind PreviewBackgroundColor, Mode=OneWay}"
-                        TintOpacity="{x:Bind PreviewBackgroundOpacity, Mode=OneWay}" />
+                        TintOpacity="{x:Bind PreviewEffectiveOpacity, Mode=OneWay}" />
                 </Border.Background>
             </Border>
+            <!--  Background image (inside window, on top of backdrop)  -->
             <local:BlurImageControl
                 HorizontalAlignment="Stretch"
                 VerticalAlignment="Stretch"
                 BlurAmount="{x:Bind PreviewBackgroundImageBlurAmount, Mode=OneWay}"
                 ImageBrightness="{x:Bind PreviewBackgroundImageBrightness, Mode=OneWay}"
+                ImageOpacity="{x:Bind PreviewBackgroundImageOpacity, Mode=OneWay}"
                 ImageSource="{x:Bind PreviewBackgroundImageSource, Mode=OneWay}"
                 ImageStretch="{x:Bind ToStretch(PreviewBackgroundImageFit), Mode=OneWay}"
                 IsHitTestVisible="False"

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

@@ -12,13 +12,11 @@ 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), OnBackdropPropertyChanged));
 
-    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, OnBackgroundImageSourceChanged));
 
-    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 PreviewBackgroundImageOpacityProperty = DependencyProperty.Register(nameof(PreviewBackgroundImageOpacity), typeof(double), typeof(CommandPalettePreview), new PropertyMetadata(1.0));
 
     public static readonly DependencyProperty PreviewBackgroundImageFitProperty = DependencyProperty.Register(nameof(PreviewBackgroundImageFit), typeof(BackgroundImageFit), typeof(CommandPalettePreview), new PropertyMetadata(default(BackgroundImageFit)));
 
@@ -30,7 +28,18 @@ public sealed partial class CommandPalettePreview : UserControl
 
     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 static readonly DependencyProperty ShowBackgroundImageProperty = DependencyProperty.Register(nameof(ShowBackgroundImage), typeof(Visibility), typeof(CommandPalettePreview), new PropertyMetadata(Visibility.Collapsed, OnVisibilityPropertyChanged));
+
+    public static readonly DependencyProperty PreviewBackdropStyleProperty = DependencyProperty.Register(nameof(PreviewBackdropStyle), typeof(BackdropStyle?), typeof(CommandPalettePreview), new PropertyMetadata(null, OnVisibilityPropertyChanged));
+
+    public static readonly DependencyProperty PreviewEffectiveOpacityProperty = DependencyProperty.Register(nameof(PreviewEffectiveOpacity), typeof(double), typeof(CommandPalettePreview), new PropertyMetadata(1.0, OnBackdropPropertyChanged));
+
+    // Computed read-only dependency properties
+    public static readonly DependencyProperty EffectiveClearColorProperty = DependencyProperty.Register(nameof(EffectiveClearColor), typeof(Color), typeof(CommandPalettePreview), new PropertyMetadata(default(Color)));
+
+    public static readonly DependencyProperty AcrylicVisibilityProperty = DependencyProperty.Register(nameof(AcrylicVisibility), typeof(Visibility), typeof(CommandPalettePreview), new PropertyMetadata(Visibility.Visible));
+
+    public static readonly DependencyProperty ClearVisibilityProperty = DependencyProperty.Register(nameof(ClearVisibility), typeof(Visibility), typeof(CommandPalettePreview), new PropertyMetadata(Visibility.Collapsed));
 
     public BackgroundImageFit PreviewBackgroundImageFit
     {
@@ -38,12 +47,6 @@ public sealed partial class CommandPalettePreview : UserControl
         set { SetValue(PreviewBackgroundImageFitProperty, value); }
     }
 
-    public double PreviewBackgroundOpacity
-    {
-        get { return (double)GetValue(PreviewBackgroundOpacityProperty); }
-        set { SetValue(PreviewBackgroundOpacityProperty, value); }
-    }
-
     public Color PreviewBackgroundColor
     {
         get { return (Color)GetValue(PreviewBackgroundColorProperty); }
@@ -56,10 +59,10 @@ public sealed partial class CommandPalettePreview : UserControl
         set { SetValue(PreviewBackgroundImageSourceProperty, value); }
     }
 
-    public int PreviewBackgroundImageOpacity
+    public double PreviewBackgroundImageOpacity
     {
-        get { return (int)GetValue(PreviewBackgroundImageOpacityProperty); }
-        set { SetValue(PreviewBackgroundImageOpacityProperty, value); }
+        get => (double)GetValue(PreviewBackgroundImageOpacityProperty);
+        set => SetValue(PreviewBackgroundImageOpacityProperty, value);
     }
 
     public double PreviewBackgroundImageBrightness
@@ -92,12 +95,48 @@ public sealed partial class CommandPalettePreview : UserControl
         set => SetValue(ShowBackgroundImageProperty, value);
     }
 
+    public BackdropStyle? PreviewBackdropStyle
+    {
+        get => (BackdropStyle?)GetValue(PreviewBackdropStyleProperty);
+        set => SetValue(PreviewBackdropStyleProperty, value);
+    }
+
+    /// <summary>
+    /// Gets or sets the effective opacity for the backdrop, pre-computed by the theme provider.
+    /// For Acrylic style: used directly as TintOpacity.
+    /// For Clear style: used to compute the alpha channel of the solid color.
+    /// </summary>
+    public double PreviewEffectiveOpacity
+    {
+        get => (double)GetValue(PreviewEffectiveOpacityProperty);
+        set => SetValue(PreviewEffectiveOpacityProperty, value);
+    }
+
+    // Computed read-only properties
+    public Color EffectiveClearColor
+    {
+        get => (Color)GetValue(EffectiveClearColorProperty);
+        private set => SetValue(EffectiveClearColorProperty, value);
+    }
+
+    public Visibility AcrylicVisibility
+    {
+        get => (Visibility)GetValue(AcrylicVisibilityProperty);
+        private set => SetValue(AcrylicVisibilityProperty, value);
+    }
+
+    public Visibility ClearVisibility
+    {
+        get => (Visibility)GetValue(ClearVisibilityProperty);
+        private set => SetValue(ClearVisibilityProperty, value);
+    }
+
     public CommandPalettePreview()
     {
         InitializeComponent();
     }
 
-    private static void PropertyChangedCallback(DependencyObject d, DependencyPropertyChangedEventArgs e)
+    private static void OnBackgroundImageSourceChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
     {
         if (d is not CommandPalettePreview preview)
         {
@@ -107,7 +146,46 @@ public sealed partial class CommandPalettePreview : UserControl
         preview.ShowBackgroundImage = e.NewValue is ImageSource ? Visibility.Visible : Visibility.Collapsed;
     }
 
-    private double ToOpacity(int value) => value / 100.0;
+    private static void OnBackdropPropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
+    {
+        if (d is not CommandPalettePreview preview)
+        {
+            return;
+        }
+
+        preview.UpdateComputedClearColor();
+    }
+
+    private static void OnVisibilityPropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
+    {
+        if (d is not CommandPalettePreview preview)
+        {
+            return;
+        }
+
+        preview.UpdateComputedVisibilityProperties();
+        preview.UpdateComputedClearColor();
+    }
+
+    private void UpdateComputedClearColor()
+    {
+        EffectiveClearColor = Color.FromArgb(
+            (byte)(PreviewEffectiveOpacity * 255),
+            PreviewBackgroundColor.R,
+            PreviewBackgroundColor.G,
+            PreviewBackgroundColor.B);
+    }
+
+    private void UpdateComputedVisibilityProperties()
+    {
+        var config = BackdropStyles.Get(PreviewBackdropStyle ?? BackdropStyle.Acrylic);
+
+        // Show backdrop effect based on style (on top of any background image)
+        AcrylicVisibility = config.PreviewBrush == PreviewBrushKind.Acrylic
+            ? Visibility.Visible : Visibility.Collapsed;
+        ClearVisibility = config.PreviewBrush == PreviewBrushKind.Solid
+            ? Visibility.Visible : Visibility.Collapsed;
+    }
 
     private double ToTintIntensity(int value) => value / 100.0;
 

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

@@ -22,7 +22,7 @@
             VerticalAlignment="Stretch"
             BlurAmount="{x:Bind ViewModel.BackgroundImageBlurAmount, Mode=OneWay}"
             ImageBrightness="{x:Bind ViewModel.BackgroundImageBrightness, Mode=OneWay}"
-            ImageOpacity="{x:Bind ViewModel.BackgroundImageOpacity, Mode=OneWay}"
+            ImageOpacity="{x:Bind ViewModel.EffectiveImageOpacity, Mode=OneWay}"
             ImageSource="{x:Bind ViewModel.BackgroundImageSource, Mode=OneWay}"
             ImageStretch="{x:Bind ViewModel.BackgroundImageStretch, Mode=OneWay}"
             IsHitTestVisible="False"

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

@@ -31,6 +31,7 @@ using Windows.ApplicationModel.Activation;
 using Windows.Foundation;
 using Windows.Graphics;
 using Windows.System;
+using Windows.UI;
 using Windows.Win32;
 using Windows.Win32.Foundation;
 using Windows.Win32.Graphics.Dwm;
@@ -80,7 +81,9 @@ public sealed partial class MainWindow : WindowEx,
     private int _sessionErrorCount;
 
     private DesktopAcrylicController? _acrylicController;
+    private MicaController? _micaController;
     private SystemBackdropConfiguration? _configurationSource;
+    private bool _isUpdatingBackdrop;
     private TimeSpan _autoGoHomeInterval = Timeout.InfiniteTimeSpan;
 
     private WindowPosition _currentWindowPosition = new();
@@ -109,7 +112,7 @@ public sealed partial class MainWindow : WindowEx,
             CommandPaletteHost.SetHostHwnd((ulong)_hwnd.Value);
         }
 
-        SetAcrylic();
+        InitializeBackdropSupport();
 
         _hiddenOwnerBehavior.ShowInTaskbar(this, Debugger.IsAttached);
 
@@ -158,7 +161,7 @@ public sealed partial class MainWindow : WindowEx,
         App.Current.Services.GetService<SettingsModel>()!.SettingsChanged += SettingsChangedHandler;
 
         // Make sure that we update the acrylic theme when the OS theme changes
-        RootElement.ActualThemeChanged += (s, e) => DispatcherQueue.TryEnqueue(UpdateAcrylic);
+        RootElement.ActualThemeChanged += (s, e) => DispatcherQueue.TryEnqueue(UpdateBackdrop);
 
         // Hardcoding event name to avoid bringing in the PowerToys.interop dependency. Event name must match CMDPAL_SHOW_EVENT from shared_constants.h
         NativeEventWaiter.WaitForEventLoop("Local\\PowerToysCmdPal-ShowEvent-62336fcd-8611-4023-9b30-091a6af4cc5a", () =>
@@ -185,7 +188,7 @@ public sealed partial class MainWindow : WindowEx,
 
     private void ThemeServiceOnThemeChanged(object? sender, ThemeChangedEventArgs e)
     {
-        UpdateAcrylic();
+        UpdateBackdrop();
     }
 
     private static void LocalKeyboardListener_OnKeyPressed(object? sender, LocalKeyboardListenerKeyPressedEventArgs e)
@@ -280,48 +283,170 @@ public sealed partial class MainWindow : WindowEx,
         _autoGoHomeTimer.Interval = _autoGoHomeInterval;
     }
 
-    private void SetAcrylic()
+    private void InitializeBackdropSupport()
     {
-        if (DesktopAcrylicController.IsSupported())
+        if (DesktopAcrylicController.IsSupported() || MicaController.IsSupported())
         {
-            // Hooking up the policy object.
             _configurationSource = new SystemBackdropConfiguration
             {
-                // Initial configuration state.
                 IsInputActive = true,
             };
-            UpdateAcrylic();
         }
     }
 
-    private void UpdateAcrylic()
+    private void UpdateBackdrop()
     {
+        // Prevent re-entrance when backdrop changes trigger ActualThemeChanged
+        if (_isUpdatingBackdrop)
+        {
+            return;
+        }
+
+        _isUpdatingBackdrop = true;
+
+        var backdrop = _themeService.Current.BackdropParameters;
+        var isImageMode = ViewModel.ShowBackgroundImage;
+        var config = BackdropStyles.Get(backdrop.Style);
+
         try
         {
-            if (_acrylicController != null)
+            switch (config.ControllerKind)
             {
-                _acrylicController.RemoveAllSystemBackdropTargets();
-                _acrylicController.Dispose();
+                case BackdropControllerKind.Solid:
+                    CleanupBackdropControllers();
+                    var tintColor = Color.FromArgb(
+                        (byte)(backdrop.EffectiveOpacity * 255),
+                        backdrop.TintColor.R,
+                        backdrop.TintColor.G,
+                        backdrop.TintColor.B);
+                    SetupTransparentBackdrop(tintColor);
+                    break;
+
+                case BackdropControllerKind.Mica:
+                case BackdropControllerKind.MicaAlt:
+                    SetupMica(backdrop, isImageMode, config.ControllerKind);
+                    break;
+
+                case BackdropControllerKind.Acrylic:
+                case BackdropControllerKind.AcrylicThin:
+                default:
+                    SetupDesktopAcrylic(backdrop, isImageMode, config.ControllerKind);
+                    break;
             }
-
-            var backdrop = _themeService.Current.BackdropParameters;
-            _acrylicController = new DesktopAcrylicController
-            {
-                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);
         }
+        finally
+        {
+            _isUpdatingBackdrop = false;
+        }
+    }
+
+    private void SetupTransparentBackdrop(Color tintColor)
+    {
+        if (SystemBackdrop is TransparentTintBackdrop existingBackdrop)
+        {
+            existingBackdrop.TintColor = tintColor;
+        }
+        else
+        {
+            SystemBackdrop = new TransparentTintBackdrop { TintColor = tintColor };
+        }
+    }
+
+    private void CleanupBackdropControllers()
+    {
+        if (_acrylicController is not null)
+        {
+            _acrylicController.RemoveAllSystemBackdropTargets();
+            _acrylicController.Dispose();
+            _acrylicController = null;
+        }
+
+        if (_micaController is not null)
+        {
+            _micaController.RemoveAllSystemBackdropTargets();
+            _micaController.Dispose();
+            _micaController = null;
+        }
+    }
+
+    private void SetupDesktopAcrylic(BackdropParameters backdrop, bool isImageMode, BackdropControllerKind kind)
+    {
+        CleanupBackdropControllers();
+
+        // Fall back to solid color if acrylic not supported
+        if (_configurationSource is null || !DesktopAcrylicController.IsSupported())
+        {
+            SetupTransparentBackdrop(backdrop.FallbackColor);
+            return;
+        }
+
+        // DesktopAcrylicController and SystemBackdrop can't be active simultaneously
+        SystemBackdrop = null;
+
+        // Image mode: no tint here, BlurImageControl handles it (avoids double-tinting)
+        var effectiveTintOpacity = isImageMode
+            ? 0.0f
+            : backdrop.EffectiveOpacity;
+
+        _acrylicController = new DesktopAcrylicController
+        {
+            Kind = kind == BackdropControllerKind.AcrylicThin
+                ? DesktopAcrylicKind.Thin
+                : DesktopAcrylicKind.Default,
+            TintColor = backdrop.TintColor,
+            TintOpacity = effectiveTintOpacity,
+            FallbackColor = backdrop.FallbackColor,
+            LuminosityOpacity = backdrop.EffectiveLuminosityOpacity,
+        };
+
+        // Requires "using WinRT;" for Window.As<>()
+        _acrylicController.AddSystemBackdropTarget(this.As<ICompositionSupportsSystemBackdrop>());
+        _acrylicController.SetSystemBackdropConfiguration(_configurationSource);
+    }
+
+    private void SetupMica(BackdropParameters backdrop, bool isImageMode, BackdropControllerKind kind)
+    {
+        CleanupBackdropControllers();
+
+        // Fall back to solid color if Mica not supported
+        if (_configurationSource is null || !MicaController.IsSupported())
+        {
+            SetupTransparentBackdrop(backdrop.FallbackColor);
+            return;
+        }
+
+        // MicaController and SystemBackdrop can't be active simultaneously
+        SystemBackdrop = null;
+        _configurationSource.Theme = _themeService.Current.Theme == ElementTheme.Dark
+            ? SystemBackdropTheme.Dark
+            : SystemBackdropTheme.Light;
+
+        var hasColorization = _themeService.Current.HasColorization || isImageMode;
+
+        _micaController = new MicaController
+        {
+            Kind = kind == BackdropControllerKind.MicaAlt
+                ? MicaKind.BaseAlt
+                : MicaKind.Base,
+        };
+
+        // Only set tint properties when colorization is active
+        // Otherwise let system handle light/dark theme defaults automatically
+        if (hasColorization)
+        {
+            // Image mode: no tint here, BlurImageControl handles it (avoids double-tinting)
+            _micaController.TintColor = backdrop.TintColor;
+            _micaController.TintOpacity = isImageMode ? 0.0f : backdrop.EffectiveOpacity;
+            _micaController.FallbackColor = backdrop.FallbackColor;
+            _micaController.LuminosityOpacity = backdrop.EffectiveLuminosityOpacity;
+        }
+
+        _micaController.AddSystemBackdropTarget(this.As<ICompositionSupportsSystemBackdrop>());
+        _micaController.SetSystemBackdropConfiguration(_configurationSource);
     }
 
     private void ShowHwnd(IntPtr hwndValue, MonitorBehavior target)
@@ -637,12 +762,8 @@ public sealed partial class MainWindow : WindowEx,
 
     private void DisposeAcrylic()
     {
-        if (_acrylicController is not null)
-        {
-            _acrylicController.Dispose();
-            _acrylicController = null!;
-            _configurationSource = null!;
-        }
+        CleanupBackdropControllers();
+        _configurationSource = null!;
     }
 
     // Updates our window s.t. the top of the window is draggable.

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

@@ -4,6 +4,7 @@
 
 using CommunityToolkit.WinUI.Helpers;
 using Microsoft.CmdPal.UI.Helpers;
+using Microsoft.CmdPal.UI.ViewModels;
 using Microsoft.CmdPal.UI.ViewModels.Services;
 using Microsoft.UI.Xaml;
 using Windows.UI;
@@ -34,7 +35,7 @@ internal sealed class ColorfulThemeProvider : IThemeProvider
         _uiSettings = uiSettings;
     }
 
-    public AcrylicBackdropParameters GetAcrylicBackdrop(ThemeContext context)
+    public BackdropParameters GetBackdropParameters(ThemeContext context)
     {
         var isLight = context.Theme == ElementTheme.Light ||
                       (context.Theme == ElementTheme.Default &&
@@ -53,7 +54,26 @@ internal sealed class ColorfulThemeProvider : IThemeProvider
         var colorIntensity = isLight ? 0.6f * colorIntensityUser : colorIntensityUser;
         var effectiveBgColor = ColorBlender.Blend(baseColor, blended, colorIntensity);
 
-        return new AcrylicBackdropParameters(effectiveBgColor, effectiveBgColor, 0.8f, 0.8f);
+        var transparencyMode = context.BackdropStyle ?? BackdropStyle.Acrylic;
+        var config = BackdropStyles.Get(transparencyMode);
+
+        // For colorful theme, boost tint opacity to show color better through blur
+        // But not for styles with fixed opacity (Mica) - they handle their own opacity
+        var baseTintOpacity = config.ControllerKind == BackdropControllerKind.Solid || !config.SupportsOpacity
+            ? (float?)null // Use default
+            : Math.Max(config.BaseTintOpacity, 0.8f);
+
+        var effectiveOpacity = config.ComputeEffectiveOpacity(context.BackdropOpacity, baseTintOpacity);
+        var effectiveLuminosityOpacity = config.SupportsOpacity
+            ? config.BaseLuminosityOpacity * context.BackdropOpacity
+            : config.BaseLuminosityOpacity;
+
+        return new BackdropParameters(
+            TintColor: effectiveBgColor,
+            FallbackColor: effectiveBgColor,
+            EffectiveOpacity: effectiveOpacity,
+            EffectiveLuminosityOpacity: effectiveLuminosityOpacity,
+            Style: transparencyMode);
     }
 
     private static class ColorBlender

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

@@ -8,14 +8,14 @@ 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"/>.
+/// Provides theme identification, resource path resolution, and creation of 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.
+/// <see cref="GetBackdropParameters(ThemeContext)"/> method computes
+/// <see cref="BackdropParameters"/> using the supplied theme context.
 /// </remarks>
 internal interface IThemeProvider
 {
@@ -30,9 +30,9 @@ internal interface IThemeProvider
     string ResourcePath { get; }
 
     /// <summary>
-    /// Creates acrylic backdrop parameters based on the provided theme context.
+    /// Creates 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);
+    /// <param name="context">The current theme context, including theme, tint, transparency mode, and optional background details.</param>
+    /// <returns>The computed <see cref="BackdropParameters"/> for the backdrop.</returns>
+    BackdropParameters GetBackdropParameters(ThemeContext context);
 }

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

@@ -2,6 +2,7 @@
 // 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.CmdPal.UI.ViewModels.Services;
 using Microsoft.UI.Xaml;
 using Windows.UI;
@@ -28,16 +29,28 @@ internal sealed class NormalThemeProvider : IThemeProvider
 
     public string ResourcePath => "ms-appx:///Styles/Theme.Normal.xaml";
 
-    public AcrylicBackdropParameters GetAcrylicBackdrop(ThemeContext context)
+    public BackdropParameters GetBackdropParameters(ThemeContext context)
     {
         var isLight = context.Theme == ElementTheme.Light ||
                       (context.Theme == ElementTheme.Default &&
                        _uiSettings.GetColorValue(UIColorType.Background).R > 128);
 
-        return new AcrylicBackdropParameters(
+        var backdropStyle = context.BackdropStyle ?? BackdropStyle.Acrylic;
+        var config = BackdropStyles.Get(backdropStyle);
+
+        // Apply light/dark theme adjustment to luminosity
+        var baseLuminosityOpacity = isLight
+            ? config.BaseLuminosityOpacity
+            : Math.Min(config.BaseLuminosityOpacity + 0.06f, 1.0f);
+
+        var effectiveOpacity = config.ComputeEffectiveOpacity(context.BackdropOpacity);
+        var effectiveLuminosityOpacity = baseLuminosityOpacity * context.BackdropOpacity;
+
+        return new BackdropParameters(
             TintColor: isLight ? LightBaseColor : DarkBaseColor,
             FallbackColor: isLight ? LightBaseColor : DarkBaseColor,
-            TintOpacity: 0.5f,
-            LuminosityOpacity: isLight ? 0.9f : 0.96f);
+            EffectiveOpacity: effectiveOpacity,
+            EffectiveLuminosityOpacity: effectiveLuminosityOpacity,
+            Style: backdropStyle);
     }
 }

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

@@ -2,12 +2,16 @@
 // 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.Media;
 using Windows.UI;
 
 namespace Microsoft.CmdPal.UI.Services;
 
+/// <summary>
+/// Input parameters for theme computation, passed to theme providers.
+/// </summary>
 internal sealed record ThemeContext
 {
     public ElementTheme Theme { get; init; }
@@ -21,4 +25,8 @@ internal sealed record ThemeContext
     public double BackgroundImageOpacity { get; init; }
 
     public int? ColorIntensity { get; init; }
+
+    public BackdropStyle? BackdropStyle { get; init; }
+
+    public float BackdropOpacity { get; init; } = 1.0f;
 }

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

@@ -72,10 +72,13 @@ internal sealed partial class ThemeService : IThemeService, IDisposable
         }
 
         // 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;
+        var themeColorIntensity = Math.Clamp(_settings.CustomThemeColorIntensity, 0, 100);
+        var imageTintIntensity = Math.Clamp(_settings.BackgroundImageTintIntensity, 0, 100);
+        var effectiveColorIntensity = _settings.ColorizationMode == ColorizationMode.Image
+            ? imageTintIntensity
+            : themeColorIntensity;
+
+        IThemeProvider provider = UseColorfulProvider(effectiveColorIntensity) ? _colorfulThemeProvider : _normalThemeProvider;
 
         // Calculate values
         var tint = _settings.ColorizationMode switch
@@ -96,32 +99,39 @@ internal sealed partial class ThemeService : IThemeService, IDisposable
         };
         var opacity = Math.Clamp(_settings.BackgroundImageOpacity, 0, 100) / 100.0;
 
-        // create context and offload to actual theme provider
+        // create input and offload to actual theme provider
         var context = new ThemeContext
         {
             Tint = tint,
-            ColorIntensity = intensity,
+            ColorIntensity = effectiveColorIntensity,
             Theme = effectiveTheme,
             BackgroundImageSource = imageSource,
             BackgroundImageStretch = stretch,
             BackgroundImageOpacity = opacity,
+            BackdropStyle = _settings.BackdropStyle,
+            BackdropOpacity = Math.Clamp(_settings.BackdropOpacity, 0, 100) / 100f,
         };
-        var backdrop = provider.GetAcrylicBackdrop(context);
+        var backdrop = provider.GetBackdropParameters(context);
         var blur = _settings.BackgroundImageBlurAmount;
         var brightness = _settings.BackgroundImageBrightness;
 
         // Create public snapshot (no provider!)
+        var hasColorization = effectiveColorIntensity > 0
+            && _settings.ColorizationMode is ColorizationMode.CustomColor or ColorizationMode.WindowsAccentColor or ColorizationMode.Image;
+
         var snapshot = new ThemeSnapshot
         {
             Tint = tint,
-            TintIntensity = intensity / 100f,
+            TintIntensity = effectiveColorIntensity / 100f,
             Theme = effectiveTheme,
             BackgroundImageSource = imageSource,
             BackgroundImageStretch = stretch,
             BackgroundImageOpacity = opacity,
             BackdropParameters = backdrop,
+            BackdropOpacity = context.BackdropOpacity,
             BlurAmount = blur,
             BackgroundBrightness = brightness / 100f,
+            HasColorization = hasColorization,
         };
 
         // Bundle with provider for internal use
@@ -138,6 +148,12 @@ internal sealed partial class ThemeService : IThemeService, IDisposable
         ThemeChanged?.Invoke(this, new ThemeChangedEventArgs());
     }
 
+    private bool UseColorfulProvider(int effectiveColorIntensity)
+    {
+        return _settings.ColorizationMode == ColorizationMode.Image
+               || (effectiveColorIntensity > 0 && _settings.ColorizationMode is ColorizationMode.CustomColor or ColorizationMode.WindowsAccentColor);
+    }
+
     private static BitmapImage? LoadImageSafe(string? path)
     {
         if (string.IsNullOrWhiteSpace(path))
@@ -195,13 +211,15 @@ internal sealed partial class ThemeService : IThemeService, IDisposable
             {
                 Tint = Colors.Transparent,
                 Theme = ElementTheme.Light,
-                BackdropParameters = new AcrylicBackdropParameters(Colors.Black, Colors.Black, 0.5f, 0.5f),
+                BackdropParameters = new BackdropParameters(Colors.Black, Colors.Black, EffectiveOpacity: 0.5f, EffectiveLuminosityOpacity: 0.5f),
+                BackdropOpacity = 1.0f,
                 BackgroundImageOpacity = 1,
                 BackgroundImageSource = null,
                 BackgroundImageStretch = Stretch.Fill,
                 BlurAmount = 0,
                 TintIntensity = 1.0f,
                 BackgroundBrightness = 0,
+                HasColorization = false,
             },
             Provider = _normalThemeProvider,
         };

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

@@ -22,18 +22,50 @@
                     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>
+                    <StackPanel
+                        Margin="0,0,0,16"
+                        HorizontalAlignment="Left"
+                        Orientation="Horizontal"
+                        Spacing="16">
+                        <ptControls:ScreenPreview>
+                            <ptControls:CommandPalettePreview
+                                PreviewBackdropStyle="{x:Bind ViewModel.Appearance.EffectiveBackdropStyle, Mode=OneWay}"
+                                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}"
+                                PreviewBackgroundImageOpacity="{x:Bind ViewModel.Appearance.EffectiveImageOpacity, Mode=OneWay}"
+                                PreviewBackgroundImageSource="{x:Bind ViewModel.Appearance.EffectiveBackgroundImageSource, Mode=OneWay}"
+                                PreviewBackgroundImageTint="{x:Bind ViewModel.Appearance.EffectiveThemeColor, Mode=OneWay}"
+                                PreviewBackgroundImageTintIntensity="{x:Bind ViewModel.Appearance.EffectiveTintIntensity, Mode=OneWay}"
+                                PreviewEffectiveOpacity="{x:Bind ViewModel.Appearance.EffectiveBackdrop.EffectiveOpacity, Mode=OneWay}"
+                                RequestedTheme="{x:Bind ViewModel.Appearance.EffectiveTheme, Mode=OneWay}" />
+                        </ptControls:ScreenPreview>
+                        <StackPanel VerticalAlignment="Bottom" Spacing="8">
+                            <Button
+                                x:Uid="Settings_AppearancePage_OpenCommandPaletteButton"
+                                MinWidth="200"
+                                HorizontalContentAlignment="Left"
+                                Click="OpenCommandPalette_Click"
+                                Style="{StaticResource SubtleButtonStyle}">
+                                <StackPanel Orientation="Horizontal" Spacing="8">
+                                    <FontIcon FontSize="16" Glyph="&#xE8A7;" />
+                                    <TextBlock x:Uid="Settings_AppearancePage_OpenCommandPaletteButton_Text" />
+                                </StackPanel>
+                            </Button>
+                            <Button
+                                x:Uid="Settings_AppearancePage_ResetAppearanceButton"
+                                MinWidth="200"
+                                HorizontalContentAlignment="Left"
+                                Command="{x:Bind ViewModel.Appearance.ResetAppearanceSettingsCommand}"
+                                Style="{StaticResource SubtleButtonStyle}">
+                                <StackPanel Orientation="Horizontal" Spacing="8">
+                                    <FontIcon FontSize="16" Glyph="&#xE72C;" />
+                                    <TextBlock x:Uid="Settings_AppearancePage_ResetAppearanceButton_Text" />
+                                </StackPanel>
+                            </Button>
+                        </StackPanel>
+                    </StackPanel>
 
                     <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}">
@@ -62,19 +94,67 @@
                         </ComboBox>
                     </controls:SettingsCard>
 
+                    <controls:SettingsExpander
+                        x:Uid="Settings_GeneralPage_BackdropStyle_SettingsCard"
+                        HeaderIcon="{ui:FontIcon Glyph=&#xF5EF;}"
+                        IsExpanded="{x:Bind ViewModel.Appearance.IsBackdropOpacityVisible, Mode=OneWay}">
+                        <ComboBox MinWidth="{StaticResource SettingActionControlMinWidth}" SelectedIndex="{x:Bind ViewModel.Appearance.BackdropStyleIndex, Mode=TwoWay}">
+                            <ComboBoxItem x:Uid="Settings_GeneralPage_BackdropStyle_Acrylic" />
+                            <ComboBoxItem x:Uid="Settings_GeneralPage_BackdropStyle_Transparent" />
+                            <ComboBoxItem x:Uid="Settings_GeneralPage_BackdropStyle_Mica" />
+                            <!--  Hidden: preview not working well, kept to preserve index mapping  -->
+                            <ComboBoxItem x:Uid="Settings_GeneralPage_BackdropStyle_AcrylicThin" Visibility="Collapsed" />
+                            <ComboBoxItem x:Uid="Settings_GeneralPage_BackdropStyle_MicaAlt" />
+                        </ComboBox>
+                        <controls:SettingsExpander.Items>
+                            <!--  Mica description (no opacity control)  -->
+                            <controls:SettingsCard
+                                x:Uid="Settings_GeneralPage_MicaBackdrop_SettingsCard"
+                                HorizontalContentAlignment="Stretch"
+                                ContentAlignment="Vertical"
+                                Visibility="{x:Bind ViewModel.Appearance.IsMicaBackdropDescriptionVisible, Mode=OneWay}">
+                                <TextBlock
+                                    x:Uid="Settings_GeneralPage_MicaBackdrop_DescriptionTextBlock"
+                                    Margin="24"
+                                    HorizontalAlignment="Stretch"
+                                    Foreground="{ThemeResource TextFillColorSecondaryBrush}"
+                                    HorizontalTextAlignment="Center"
+                                    TextAlignment="Center"
+                                    TextWrapping="WrapWholeWords" />
+                            </controls:SettingsCard>
+                            <!--  Opacity slider (for non-Mica styles)  -->
+                            <controls:SettingsCard x:Uid="Settings_GeneralPage_BackdropOpacity_SettingsCard" Visibility="{x:Bind ViewModel.Appearance.IsBackdropOpacityVisible, Mode=OneWay}">
+                                <Slider
+                                    MinWidth="{StaticResource SettingActionControlMinWidth}"
+                                    Maximum="100"
+                                    Minimum="0"
+                                    StepFrequency="1"
+                                    Value="{x:Bind ViewModel.Appearance.BackdropOpacity, Mode=TwoWay}" />
+                            </controls:SettingsCard>
+                        </controls:SettingsExpander.Items>
+                    </controls:SettingsExpander>
+
                     <controls:SettingsExpander
                         x:Uid="Settings_GeneralPage_Background_SettingsExpander"
                         HeaderIcon="{ui:FontIcon Glyph=&#xE790;}"
+                        IsEnabled="{x:Bind ViewModel.Appearance.IsBackgroundSettingsEnabled, Mode=OneWay}"
                         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>
+                        <Grid>
+                            <ComboBox
+                                x:Uid="Settings_GeneralPage_ColorizationMode"
+                                MinWidth="{StaticResource SettingActionControlMinWidth}"
+                                SelectedIndex="{x:Bind ViewModel.Appearance.ColorizationModeIndex, Mode=TwoWay}"
+                                Visibility="{x:Bind ViewModel.Appearance.IsBackgroundSettingsEnabled, Mode=OneWay}">
+                                <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>
+                            <TextBlock
+                                x:Uid="Settings_GeneralPage_Background_NotAvailable"
+                                Foreground="{ThemeResource TextFillColorSecondaryBrush}"
+                                Visibility="{x:Bind ViewModel.Appearance.IsBackgroundNotAvailableVisible, Mode=OneWay}" />
+                        </Grid>
                         <controls:SettingsExpander.Items>
                             <!--  none  -->
                             <controls:SettingsCard
@@ -155,7 +235,7 @@
                                     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}">
+                            <controls:SettingsCard x:Uid="Settings_GeneralPage_BackgroundTintIntensity_SettingsCard" Visibility="{x:Bind ViewModel.Appearance.IsColorIntensityVisible, Mode=OneWay}">
                                 <Slider
                                     MinWidth="{StaticResource SettingActionControlMinWidth}"
                                     Maximum="100"
@@ -163,9 +243,17 @@
                                     StepFrequency="1"
                                     Value="{x:Bind ViewModel.Appearance.ColorIntensity, Mode=TwoWay}" />
                             </controls:SettingsCard>
+                            <controls:SettingsCard x:Uid="Settings_GeneralPage_ImageTintIntensity_SettingsCard" Visibility="{x:Bind ViewModel.Appearance.IsImageTintIntensityVisible, Mode=OneWay}">
+                                <Slider
+                                    MinWidth="{StaticResource SettingActionControlMinWidth}"
+                                    Maximum="100"
+                                    Minimum="0"
+                                    StepFrequency="1"
+                                    Value="{x:Bind ViewModel.Appearance.BackgroundImageTintIntensity, 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}">
+                            <!--  Reset appearance properties  -->
+                            <controls:SettingsCard x:Uid="Settings_GeneralPage_BackgroundImage_ResetProperties_SettingsCard" Visibility="{x:Bind ViewModel.Appearance.IsResetButtonVisible, Mode=OneWay}">
                                 <StackPanel Orientation="Horizontal" Spacing="8">
                                     <Button x:Uid="Settings_GeneralPage_Background_ResetImagePropertiesButton" Command="{x:Bind ViewModel.Appearance.ResetBackgroundImagePropertiesCommand}" />
                                 </StackPanel>

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

@@ -3,8 +3,13 @@
 // See the LICENSE file in the project root for more information.
 
 using System.Diagnostics;
+using CommunityToolkit.Mvvm.Messaging;
 using ManagedCommon;
+using Microsoft.CmdPal.Core.ViewModels.Messages;
+using Microsoft.CmdPal.UI.Events;
+using Microsoft.CmdPal.UI.Messages;
 using Microsoft.CmdPal.UI.ViewModels;
+using Microsoft.CmdPal.UI.ViewModels.Messages;
 using Microsoft.CmdPal.UI.ViewModels.Services;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.UI;
@@ -12,6 +17,7 @@ using Microsoft.UI.Xaml;
 using Microsoft.UI.Xaml.Controls;
 using Microsoft.UI.Xaml.Documents;
 using Microsoft.Windows.Storage.Pickers;
+using Windows.Win32.Foundation;
 
 namespace Microsoft.CmdPal.UI.Settings;
 
@@ -86,4 +92,9 @@ public sealed partial class AppearancePage : Page
             }
         });
     }
+
+    private void OpenCommandPalette_Click(object sender, RoutedEventArgs e)
+    {
+        WeakReferenceMessenger.Default.Send<HotkeySummonMessage>(new(string.Empty, HWND.Null));
+    }
 }

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

@@ -1,17 +1,17 @@
 <?xml version="1.0" encoding="utf-8"?>
 <root>
-  <!-- 
-    Microsoft ResX Schema 
-    
+  <!--
+    Microsoft ResX Schema
+
     Version 2.0
-    
-    The primary goals of this format is to allow a simple XML format 
-    that is mostly human readable. The generation and parsing of the 
-    various data types are done through the TypeConverter classes 
+
+    The primary goals of this format is to allow a simple XML format
+    that is mostly human readable. The generation and parsing of the
+    various data types are done through the TypeConverter classes
     associated with the data types.
-    
+
     Example:
-    
+
     ... ado.net/XML headers & schema ...
     <resheader name="resmimetype">text/microsoft-resx</resheader>
     <resheader name="version">2.0</resheader>
@@ -26,36 +26,36 @@
         <value>[base64 mime encoded string representing a byte array form of the .NET Framework object]</value>
         <comment>This is a comment</comment>
     </data>
-                
-    There are any number of "resheader" rows that contain simple 
+
+    There are any number of "resheader" rows that contain simple
     name/value pairs.
-    
-    Each data row contains a name, and value. The row also contains a 
-    type or mimetype. Type corresponds to a .NET class that support 
-    text/value conversion through the TypeConverter architecture. 
-    Classes that don't support this are serialized and stored with the 
+
+    Each data row contains a name, and value. The row also contains a
+    type or mimetype. Type corresponds to a .NET class that support
+    text/value conversion through the TypeConverter architecture.
+    Classes that don't support this are serialized and stored with the
     mimetype set.
-    
-    The mimetype is used for serialized objects, and tells the 
-    ResXResourceReader how to depersist the object. This is currently not 
+
+    The mimetype is used for serialized objects, and tells the
+    ResXResourceReader how to depersist the object. This is currently not
     extensible. For a given mimetype the value must be set accordingly:
-    
-    Note - application/x-microsoft.net.object.binary.base64 is the format 
-    that the ResXResourceWriter will generate, however the reader can 
+
+    Note - application/x-microsoft.net.object.binary.base64 is the format
+    that the ResXResourceWriter will generate, however the reader can
     read any of the formats listed below.
-    
+
     mimetype: application/x-microsoft.net.object.binary.base64
-    value   : The object must be serialized with 
+    value   : The object must be serialized with
             : System.Runtime.Serialization.Formatters.Binary.BinaryFormatter
             : and then encoded with base64 encoding.
-    
+
     mimetype: application/x-microsoft.net.object.soap.base64
-    value   : The object must be serialized with 
+    value   : The object must be serialized with
             : System.Runtime.Serialization.Formatters.Soap.SoapFormatter
             : and then encoded with base64 encoding.
 
     mimetype: application/x-microsoft.net.object.bytearray.base64
-    value   : The object must be serialized into a byte array 
+    value   : The object must be serialized into a byte array
             : using a System.ComponentModel.TypeConverter
             : and then encoded with base64 encoding.
     -->
@@ -577,6 +577,9 @@ Right-click to remove the key combination, thereby deactivating the shortcut.</v
   <data name="Settings_GeneralPage_BackgroundTintIntensity_SettingsCard.Header" xml:space="preserve">
     <value>Color intensity</value>
   </data>
+  <data name="Settings_GeneralPage_ImageTintIntensity_SettingsCard.Header" xml:space="preserve">
+    <value>Color intensity</value>
+  </data>
   <data name="OptionalColorPickerButton_UnsetTextBlock.Text" xml:space="preserve">
     <value>Choose color</value>
   </data>
@@ -668,7 +671,7 @@ Right-click to remove the key combination, thereby deactivating the shortcut.</v
     <value>Background image</value>
   </data>
   <data name="Settings_GeneralPage_NoBackground_DescriptionTextBlock.Text" xml:space="preserve">
-    <value>No settings</value>
+    <value>No additional settings are available.</value>
   </data>
   <data name="Settings_GeneralPage_Background_SettingsExpander.Header" xml:space="preserve">
     <value>Background</value>
@@ -676,6 +679,9 @@ Right-click to remove the key combination, thereby deactivating the shortcut.</v
   <data name="Settings_GeneralPage_Background_SettingsExpander.Description" xml:space="preserve">
     <value>Choose a custom background color or image</value>
   </data>
+  <data name="Settings_GeneralPage_Background_NotAvailable.Text" xml:space="preserve">
+    <value>Not available with Mica</value>
+  </data>
   <data name="Settings_GeneralPage_WindowsAccentColor_SettingsCard.Header" xml:space="preserve">
     <value>System accent color</value>
   </data>
@@ -692,7 +698,7 @@ Right-click to remove the key combination, thereby deactivating the shortcut.</v
     <value>Restore defaults</value>
   </data>
   <data name="Settings_GeneralPage_Background_ResetImagePropertiesButton.Content" xml:space="preserve">
-    <value>Reset</value>
+    <value>Reset image settings</value>
   </data>
   <data name="Settings_GeneralPage_WindowsAccentColor_SettingsCard_Description1.Text" xml:space="preserve">
     <value>Change the system accent in Windows Settings:</value>
@@ -727,4 +733,45 @@ Right-click to remove the key combination, thereby deactivating the shortcut.</v
   <data name="Settings_GeneralPage_VersionNo" xml:space="preserve">
     <value>Version {0}</value>
   </data>
+  <data name="Settings_GeneralPage_BackdropOpacity_SettingsCard.Header" xml:space="preserve">
+    <value>Opacity</value>
+  </data>
+  <data name="Settings_GeneralPage_BackdropStyle_SettingsCard.Header" xml:space="preserve">
+    <value>Material</value>
+  </data>
+  <data name="Settings_GeneralPage_BackdropStyle_SettingsCard.Description" xml:space="preserve">
+    <value>Select the visual material used for the window background</value>
+  </data>
+  <data name="Settings_GeneralPage_BackdropStyle_Acrylic.Content" xml:space="preserve">
+    <value>Acrylic (default)</value>
+  </data>
+  <data name="Settings_GeneralPage_BackdropStyle_Transparent.Content" xml:space="preserve">
+    <value>Transparent</value>
+  </data>
+  <data name="Settings_GeneralPage_BackdropStyle_Mica.Content" xml:space="preserve">
+    <value>Mica</value>
+  </data>
+  <data name="Settings_GeneralPage_BackdropStyle_AcrylicThin.Content" xml:space="preserve">
+    <value>Thin Acrylic</value>
+  </data>
+  <data name="Settings_GeneralPage_BackdropStyle_MicaAlt.Content" xml:space="preserve">
+    <value>Mica Alt</value>
+  </data>
+  <data name="Settings_GeneralPage_MicaBackdrop_DescriptionTextBlock.Text" xml:space="preserve">
+    <value>Mica automatically adapts to your desktop wallpaper. Custom backgrounds and opacity settings are not available for this material.</value>
+  </data>
+  <data name="Settings_AppearancePage_OpenCommandPaletteButton.[using:Microsoft.UI.Xaml.Automation]AutomationProperties.Name" xml:space="preserve">
+    <value>Open Command Palette</value>
+    <comment>Button to open the Command Palette window to preview appearance changes</comment>
+  </data>
+  <data name="Settings_AppearancePage_OpenCommandPaletteButton_Text.Text" xml:space="preserve">
+    <value>Open Command Palette</value>
+  </data>
+  <data name="Settings_AppearancePage_ResetAppearanceButton.[using:Microsoft.UI.Xaml.Automation]AutomationProperties.Name" xml:space="preserve">
+    <value>Reset appearance settings</value>
+    <comment>Button to reset all appearance settings to their default values</comment>
+  </data>
+  <data name="Settings_AppearancePage_ResetAppearanceButton_Text.Text" xml:space="preserve">
+    <value>Reset to defaults</value>
+  </data>
 </root>