dotnet
diff --git a/‎Documentation/projects-and-assemblies.md
+5-2 b/‎Documentation/projects-and-assemblies.md
+5-2
diff --git a/‎Microsoft.Dotnet.Wpf.sln
+38 b/‎Microsoft.Dotnet.Wpf.sln
+38
diff --git a/‎eng/WpfArcadeSdk/tools/GenApi.props
+1 b/‎eng/WpfArcadeSdk/tools/GenApi.props
+1
diff --git a/‎eng/WpfArcadeSdk/tools/ShippingProjects.props
+4 b/‎eng/WpfArcadeSdk/tools/ShippingProjects.props
+4
diff --git a/‎eng/WpfArcadeSdk/tools/WpfProjectReference.targets
+1-1 b/‎eng/WpfArcadeSdk/tools/WpfProjectReference.targets
+1-1
diff --git a/‎src/Microsoft.DotNet.Wpf/src/PresentationCore/MS/internal/WindowsRuntime/Windows/UI/ViewManagement/NativeMethods.cs
+3 b/‎src/Microsoft.DotNet.Wpf/src/PresentationCore/MS/internal/WindowsRuntime/Windows/UI/ViewManagement/NativeMethods.cs
+3
diff --git a/‎src/Microsoft.DotNet.Wpf/src/PresentationCore/MS/internal/WindowsRuntime/Windows/UI/ViewManagement/UISettings.cs
+187 b/‎src/Microsoft.DotNet.Wpf/src/PresentationCore/MS/internal/WindowsRuntime/Windows/UI/ViewManagement/UISettings.cs
+187
diff --git a/‎src/Microsoft.DotNet.Wpf/src/PresentationCore/MS/internal/WindowsRuntime/Windows/UI/ViewManagement/UISettingsRcw.cs
+73 b/‎src/Microsoft.DotNet.Wpf/src/PresentationCore/MS/internal/WindowsRuntime/Windows/UI/ViewManagement/UISettingsRcw.cs
+73
@@ -118,9 +118,11 @@ The following assemblies are being produced today:
     |   PresentationFramework.dll
     |   PresentationFramework.Luna.dll
     |   PresentationFramework.Luna.pdb
-    |   PresentationFramework.pdb
+    |   PresentationFramework.pdb 
     |   PresentationFramework.Royale.dll
     |   PresentationFramework.Royale.pdb
+    |   PresentationFramework.Fluent.dll
+    |   PresentationFramework.Fluent.pdb
     |   PresentationUI.dll
     |   PresentationUI.pdb
     |   ReachFramework.dll
@@ -452,7 +454,8 @@ src\Themes\PresentationFramework.Luna\PresentationFramework.Luna.csproj
 src\Themes\PresentationFramework.Luna\ref\PresentationFramework.Luna-ref.csproj
 src\Themes\PresentationFramework.Royale\PresentationFramework.Royale.csproj
 src\Themes\PresentationFramework.Royale\ref\PresentationFramework.Royale-ref.csproj
-
+src\Themes\PresentationFramework.Fluent\PresentationFramework.Fluent.csproj
+src\Themes\PresentationFramework.Fluent\ref\PresentationFramework.Fluent-ref.csproj
 src\UIAutomation\UIAutomationClient\UIAutomationClient.csproj
 src\UIAutomation\UIAutomationClient\ref\UIAutomationClient-ref.csproj
 src\UIAutomation\UIAutomationClientSideProviders\UIAutomationClientSideProviders.csproj
 
@@ -249,6 +249,10 @@ Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "UnitTests", "UnitTests", "{
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "System.Xaml.Tests", "src\Microsoft.DotNet.Wpf\tests\UnitTests\System.Xaml.Tests\System.Xaml.Tests.csproj", "{B2F2A89C-55C9-41B1-A645-0948609BD8BE}"
 EndProject
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "PresentationFramework.Fluent", "src\Microsoft.DotNet.Wpf\src\Themes\PresentationFramework.Fluent\PresentationFramework.Fluent.csproj", "{3F2C0E0E-BB13-46D9-8D9A-08256A49ECA9}"
+EndProject
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "PresentationFramework.Fluent-ref", "src\Microsoft.DotNet.Wpf\src\Themes\PresentationFramework.Fluent\ref\PresentationFramework.Fluent-ref.csproj", "{3C43C553-2C1F-4EB9-8BF8-371D4A42E0FD}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -1942,6 +1946,38 @@ Global
 		{B2F2A89C-55C9-41B1-A645-0948609BD8BE}.Release|x86.ActiveCfg = Release|Win32
 		{B2F2A89C-55C9-41B1-A645-0948609BD8BE}.Release|x86.Build.0 = Release|Win32
 		{B2F2A89C-55C9-41B1-A645-0948609BD8BE}.Release|x86.Deploy.0 = Release|Win32
+		{3F2C0E0E-BB13-46D9-8D9A-08256A49ECA9}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{3F2C0E0E-BB13-46D9-8D9A-08256A49ECA9}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{3F2C0E0E-BB13-46D9-8D9A-08256A49ECA9}.Debug|ARM64.ActiveCfg = Debug|arm64
+		{3F2C0E0E-BB13-46D9-8D9A-08256A49ECA9}.Debug|ARM64.Build.0 = Debug|arm64
+		{3F2C0E0E-BB13-46D9-8D9A-08256A49ECA9}.Debug|x64.ActiveCfg = Debug|x64
+		{3F2C0E0E-BB13-46D9-8D9A-08256A49ECA9}.Debug|x64.Build.0 = Debug|x64
+		{3F2C0E0E-BB13-46D9-8D9A-08256A49ECA9}.Debug|x86.ActiveCfg = Debug|Any CPU
+		{3F2C0E0E-BB13-46D9-8D9A-08256A49ECA9}.Debug|x86.Build.0 = Debug|Any CPU
+		{3F2C0E0E-BB13-46D9-8D9A-08256A49ECA9}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{3F2C0E0E-BB13-46D9-8D9A-08256A49ECA9}.Release|Any CPU.Build.0 = Release|Any CPU
+		{3F2C0E0E-BB13-46D9-8D9A-08256A49ECA9}.Release|ARM64.ActiveCfg = Release|arm64
+		{3F2C0E0E-BB13-46D9-8D9A-08256A49ECA9}.Release|ARM64.Build.0 = Release|arm64
+		{3F2C0E0E-BB13-46D9-8D9A-08256A49ECA9}.Release|x64.ActiveCfg = Release|x64
+		{3F2C0E0E-BB13-46D9-8D9A-08256A49ECA9}.Release|x64.Build.0 = Release|x64
+		{3F2C0E0E-BB13-46D9-8D9A-08256A49ECA9}.Release|x86.ActiveCfg = Release|Any CPU
+		{3F2C0E0E-BB13-46D9-8D9A-08256A49ECA9}.Release|x86.Build.0 = Release|Any CPU
+		{3C43C553-2C1F-4EB9-8BF8-371D4A42E0FD}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{3C43C553-2C1F-4EB9-8BF8-371D4A42E0FD}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{3C43C553-2C1F-4EB9-8BF8-371D4A42E0FD}.Debug|ARM64.ActiveCfg = Debug|arm64
+		{3C43C553-2C1F-4EB9-8BF8-371D4A42E0FD}.Debug|ARM64.Build.0 = Debug|arm64
+		{3C43C553-2C1F-4EB9-8BF8-371D4A42E0FD}.Debug|x64.ActiveCfg = Debug|x64
+		{3C43C553-2C1F-4EB9-8BF8-371D4A42E0FD}.Debug|x64.Build.0 = Debug|x64
+		{3C43C553-2C1F-4EB9-8BF8-371D4A42E0FD}.Debug|x86.ActiveCfg = Debug|Any CPU
+		{3C43C553-2C1F-4EB9-8BF8-371D4A42E0FD}.Debug|x86.Build.0 = Debug|Any CPU
+		{3C43C553-2C1F-4EB9-8BF8-371D4A42E0FD}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{3C43C553-2C1F-4EB9-8BF8-371D4A42E0FD}.Release|Any CPU.Build.0 = Release|Any CPU
+		{3C43C553-2C1F-4EB9-8BF8-371D4A42E0FD}.Release|ARM64.ActiveCfg = Release|arm64
+		{3C43C553-2C1F-4EB9-8BF8-371D4A42E0FD}.Release|ARM64.Build.0 = Release|arm64
+		{3C43C553-2C1F-4EB9-8BF8-371D4A42E0FD}.Release|x64.ActiveCfg = Release|x64
+		{3C43C553-2C1F-4EB9-8BF8-371D4A42E0FD}.Release|x64.Build.0 = Release|x64
+		{3C43C553-2C1F-4EB9-8BF8-371D4A42E0FD}.Release|x86.ActiveCfg = Release|Any CPU
+		{3C43C553-2C1F-4EB9-8BF8-371D4A42E0FD}.Release|x86.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE
@@ -2062,6 +2098,8 @@ Global
 		{34B64A4A-7C83-4F92-8C47-80E9FA10D660} = {C9ECC1A1-917F-43D3-B340-2035B4938507}
 		{A48B585E-6AB0-4F8D-8484-77F37CB44437} = {34B64A4A-7C83-4F92-8C47-80E9FA10D660}
 		{B2F2A89C-55C9-41B1-A645-0948609BD8BE} = {A48B585E-6AB0-4F8D-8484-77F37CB44437}
+		{3F2C0E0E-BB13-46D9-8D9A-08256A49ECA9} = {5ACFB055-649D-4A01-98C2-B0BFE7E543D6}
+		{3C43C553-2C1F-4EB9-8BF8-371D4A42E0FD} = {60F4058B-D35B-42D2-B276-D44B3AC579BD}
 	EndGlobalSection
 	GlobalSection(ExtensibilityGlobals) = postSolution
 		SolutionGuid = {B4340004-DAC0-497D-B69D-CFA7CD93F567}
 
@@ -10,6 +10,7 @@
       PresentationFramework.Classic;
       PresentationFramework.Luna;
       PresentationFramework.Royale;
+      PresentationFramework.Fluent;
       ReachFramework;
       System.Windows.Controls.Ribbon;
       System.Windows.Input.Manipulations;
 
@@ -28,6 +28,7 @@
       PresentationFramework.Classic;
       PresentationFramework.Luna;
       PresentationFramework.Royale;
+      PresentationFramework.Fluent;
       WindowsFormsIntegration;
       PenImc;
       wpfgfx;
@@ -98,6 +99,7 @@
       PresentationFramework.Classic-ref;
       PresentationFramework.Luna-ref;
       PresentationFramework.Royale-ref;
+      PresentationFramework.Fluent-ref;
       PresentationUI-ref;
       System.Printing-ref;
       System.Windows.Controls.Ribbon-ref;
@@ -136,6 +138,8 @@
       PresentationFramework.Luna-ref;
       PresentationFramework.Royale;
       PresentationFramework.Royale-ref;
+      PresentationFramework.Fluent;
+      PresentationFramework.Fluent-ref;
       PresentationUI;
       ReachFramework;
       ReachFramework-ref;
 
@@ -47,7 +47,7 @@
     <WpfProjectPath Include="PresentationFramework.Classic" ProjectPath="$(WpfSourceDir)Themes\PresentationFramework.Classic\PresentationFramework.Classic.csproj" />
     <WpfProjectPath Include="PresentationFramework.Luna" ProjectPath="$(WpfSourceDir)Themes\PresentationFramework.Luna\PresentationFramework.Luna.csproj" />
     <WpfProjectPath Include="PresentationFramework.Royale" ProjectPath="$(WpfSourceDir)Themes\PresentationFramework.Royale\PresentationFramework.Royale.csproj" />
-
+    <WpfProjectPath Include="PresentationFramework.Fluent" ProjectPath="$(WpfSourceDir)Themes\PresentationFramework.Fluent\PresentationFramework.Fluent.csproj" />
     <WpfProjectPath Include="UIAutomationTypes" ProjectPath="$(WpfSourceDir)UIAutomation\UIAutomationTypes\UIAutomationTypes.csproj" />
     <WpfProjectPath Include="UIAutomationProvider" ProjectPath="$(WpfSourceDir)UIAutomation\UIAutomationProvider\UIAutomationProvider.csproj" />
     <WpfProjectPath Include="UIAutomationClient" ProjectPath="$(WpfSourceDir)UIAutomation\UIAutomationClient\UIAutomationClient.csproj" />
 
@@ -31,6 +31,9 @@ internal static extern unsafe int WindowsCreateString([MarshalAs(UnmanagedType.L
             [DllImport(DllImport.ApiSetWinRT, CallingConvention = CallingConvention.StdCall)]
             internal static extern unsafe int RoGetActivationFactory(IntPtr runtimeClassId, ref Guid iid, [MarshalAs(UnmanagedType.Interface)] out object factory);
 
+            [DllImport(DllImport.ApiSetWinRT, CallingConvention = CallingConvention.StdCall)]
+            internal static extern unsafe int RoActivateInstance(IntPtr runtimeClassId, [MarshalAs(UnmanagedType.Interface)] out object instance);
+
             internal const int E_NOINTERFACE = unchecked((int)0x80004002);
 
             internal const int REGDB_E_CLASSNOTREG = unchecked((int)0x80040154);
 
@@ -0,0 +1,187 @@
+using System;
+using System.IO;
+using System.Reflection;
+using System.Runtime.InteropServices;
+using System.Security;
+using System.Windows;
+using System.Windows.Interop;
+using System.Windows.Media;
+using MS.Internal.PresentationCore.WindowsRuntime;
+
+namespace MS.Internal.WindowsRuntime
+{
+    namespace Windows.UI.ViewManagement
+    {
+        internal class UISettings : IDisposable
+        {
+            private readonly bool _isSupported;
+
+            private UISettingsRCW.IUISettings3 _uisettings;
+
+            private static readonly Color _fallbackAccentColor = Color.FromArgb(0xff, 0x00, 0x78, 0xd4);
+
+            private Color _accentColor, _accentLight1, _accentLight2, _accentLight3;
+            private Color _accentDark1, _accentDark2, _accentDark3;
+
+            private bool _useFallbackColor = false;
+
+            internal UISettings()
+            {
+                _isSupported = false;
+
+                try
+                {
+                    _uisettings = GetWinRTInstance() as UISettingsRCW.IUISettings3;
+                }
+                catch (COMException)
+                {
+                    // We don't want to throw any exceptions here.
+                    // If we can't get the instance, we will use the default accent color.
+                }
+
+                if (_uisettings != null)
+                {
+                    _isSupported = true;
+                    TryUpdateAccentColors();
+                }
+            }
+
+            /// <summary>
+            ///     Gets the accent color value for the desired color type.
+            /// </summary>
+            /// <returns>
+            ///     Returns true if fetching value from UISettings was successful.
+            ///     If the fetch fails, we return false and return the default accent color.
+            /// </returns>
+            internal bool TryGetColorValue(UISettingsRCW.UIColorType desiredColor, out Color color)
+            {                
+                if(_isSupported)
+                {
+                    try
+                    {
+                        var uiColor = _uisettings.GetColorValue(desiredColor);
+                        color = Color.FromArgb(uiColor.A, uiColor.R, uiColor.G, uiColor.B);
+                        return true;
+                    }
+                    catch (COMException)
+                    {
+                        // We don't want to throw any exceptions here.
+                        // If we can't get the instance, we will use the default accent color.
+                    }
+                }
+                color = _fallbackAccentColor;
+                return false;
+            }
+
+            /// <summary>
+            ///   Tries to update the accent colors properties.
+            ///   If any call to TryGetColorValue fails, we set _useFallbackColor to true.
+            ///   After which all the accent values will be the default color.
+            ///   This is to ensure that we don't have inconsistent set of accent color values stored.
+            /// </summary>
+            internal void TryUpdateAccentColors()
+            {
+                _useFallbackColor = true;
+
+                if(_isSupported)
+                {
+                    try
+                    {
+                        if(TryGetColorValue(UISettingsRCW.UIColorType.Accent, out Color systemAccent))
+                        {
+                            // For verifying if any of the calls to TryGetColorValue fails.
+                            bool result = true;
+                            if(_accentColor != systemAccent)
+                            {
+                                result &= TryGetColorValue(UISettingsRCW.UIColorType.AccentLight1, out _accentLight1);
+                                result &= TryGetColorValue(UISettingsRCW.UIColorType.AccentLight2, out _accentLight2);
+                                result &= TryGetColorValue(UISettingsRCW.UIColorType.AccentLight3, out _accentLight3);
+                                result &= TryGetColorValue(UISettingsRCW.UIColorType.AccentDark1, out _accentDark1);
+                                result &= TryGetColorValue(UISettingsRCW.UIColorType.AccentDark2, out _accentDark2);
+                                result &= TryGetColorValue(UISettingsRCW.UIColorType.AccentDark3, out _accentDark3);
+                                _accentColor = systemAccent;
+                            }
+                            // If result is false, hence atleast one call, use fallback values.
+                            _useFallbackColor = !result;
+                        }
+                    }
+                    catch
+                    {
+                        // We don't want to throw any exceptions here.
+                        // If we can't get any one of the color values, we will use the default accent color.
+                    }
+                }
+            }
+
+            /// <summary>
+            ///   Gets the WinRT instance of UISettings.
+            /// </summary>
+            private static object GetWinRTInstance()
+            {
+                object winRtInstance = null;
+                try
+                {
+                    winRtInstance = UISettingsRCW.GetUISettingsInstance();
+                }
+                catch (Exception e) when (e is TypeLoadException || e is FileNotFoundException)
+                {
+                    winRtInstance = null;
+                }
+
+                return winRtInstance;
+            }
+
+            #region Color Properties
+
+            internal Color AccentColor => _useFallbackColor ? _fallbackAccentColor : _accentColor;
+            internal Color AccentLight1 => _useFallbackColor ? _fallbackAccentColor : _accentLight1;
+            internal Color AccentLight2 => _useFallbackColor ? _fallbackAccentColor : _accentLight2;
+            internal Color AccentLight3 => _useFallbackColor ? _fallbackAccentColor : _accentLight3;
+            internal Color AccentDark1 => _useFallbackColor ? _fallbackAccentColor : _accentDark1;
+            internal Color AccentDark2 => _useFallbackColor ? _fallbackAccentColor : _accentDark2;
+            internal Color AccentDark3 => _useFallbackColor ? _fallbackAccentColor : _accentDark3;
+
+            #endregion
+
+            #region IDisposable
+
+            bool _disposed = false;
+
+            ~UISettings()
+            {
+                Dispose(false);
+            }
+
+            public void Dispose()
+            {
+                Dispose(true);
+                GC.SuppressFinalize(this);
+            }
+
+            private void Dispose(bool disposing)
+            {
+                if (!_disposed)
+                {
+                    if (_uisettings != null)
+                    {
+                        try
+                        {
+                            // Release the _uiSettings instance here
+                            Marshal.ReleaseComObject(_uisettings);
+                        }
+                        catch
+                        {
+                            // Don't want to raise any exceptions in a finalizer, eat them here
+                        }
+
+                        _uisettings = null;
+                    }
+
+                    _disposed = true;
+                }
+            }
+
+            #endregion
+        }
+    }
+}
@@ -0,0 +1,73 @@
+using System;
+using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
+using System.Security;
+using System.Windows.Media;
+
+namespace MS.Internal.WindowsRuntime
+{
+    namespace Windows.UI.ViewManagement
+    {
+        /// <summary>
+        /// Contains internal RCWs for invoking the UISettings
+        /// </summary>
+        internal static class UISettingsRCW
+        {
+
+            public static object GetUISettingsInstance()
+            {
+                const string typeName = "Windows.UI.ViewManagement.UISettings";
+                IntPtr hstring = IntPtr.Zero;
+                int hr = NativeMethods.WindowsCreateString(typeName, typeName.Length, out hstring);
+                Marshal.ThrowExceptionForHR(hr);
+                try
+                {
+                    hr = NativeMethods.RoActivateInstance(hstring, out object instance);
+                    Marshal.ThrowExceptionForHR(hr);
+                    return instance;
+                }
+                finally
+                {
+                    hr = NativeMethods.WindowsDeleteString(hstring);
+                    Marshal.ThrowExceptionForHR(hr);
+                }
+            }
+
+            [Guid("03021BE4-5254-4781-8194-5168F7D06D7B"), InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
+            [ComImport]
+            internal interface IUISettings3
+            {
+                void GetIids(out uint iidCount, out IntPtr iids);
+
+                void GetRuntimeClassName(out string className);
+
+                void GetTrustLevel(out TrustLevel TrustLevel);
+
+                UIColor GetColorValue(UIColorType desiredColor);
+            }
+
+            internal enum TrustLevel
+            {
+                BaseTrust,
+                PartialTrust,
+                FullTrust
+            }
+
+            public enum UIColorType
+            {
+                Background = 0,
+                Foreground = 1,
+                AccentDark3 = 2,
+                AccentDark2 = 3,
+                AccentDark1 = 4,
+                Accent = 5,
+                AccentLight1 = 6,
+                AccentLight2 = 7,
+                AccentLight3 = 8,
+                Complement = 9
+            }
+
+            internal readonly record struct UIColor(byte A, byte R, byte G, byte B);
+        }
+    }
+}