PowerToys/src/modules/launcher/PowerLauncher/Themes/Light.xaml

<ResourceDictionary
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    xmlns:options="http://schemas.microsoft.com/winfx/2006/xaml/presentation/options"
    xmlns:system="clr-namespace:System;assembly=System.Runtime"
    mc:Ignorable="options">

    <!--  Metadata  -->
    <system:String x:Key="Theme.Name">Light.Accent1</system:String>
    <system:String x:Key="Theme.Origin">PowerToysRun</system:String>
    <system:String x:Key="Theme.DisplayName">Accent1 (Light)</system:String>
    <system:String x:Key="Theme.BaseColorScheme">Light</system:String>
    <system:String x:Key="Theme.ColorScheme">Accent1</system:String>
    <Color x:Key="Theme.PrimaryAccentColor">White</Color>
    <system:Boolean x:Key="Theme.IsHighContrast">False</system:Boolean>
</ResourceDictionary>