fix #13813 : Dark Mode: The ForeColor & BackColor properties are not working for the controls (#13818)

Fixes #13813

## Proposed changes

Add code to see if BackColor or ForeColor is specified in dark mode, if
so then use the specified color, if not then let the renderer decide the
color.

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## Customer Impact

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## Regression? 

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## Risk

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## Screenshots 

### Before

<img width="589" height="574" alt="image"
src="https://github.com/user-attachments/assets/b5c2281e-937f-4e44-8841-552d22fceed7"
/>


### After
<img width="590" height="571" alt="image"
src="https://github.com/user-attachments/assets/9604e7ce-1d69-4b63-a0e1-b57938f9752d"
/>

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## Test methodology 

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## Accessibility testing  



## Test environment(s) 

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Author: KlausLoeffelmann

src/System.Windows.Forms/PublicAPI.Unshipped.txt

@@ -1,3 +1,5 @@
+override System.Windows.Forms.ButtonBase.OnBackColorChanged(System.EventArgs! e) -> void
+override System.Windows.Forms.ButtonBase.OnForeColorChanged(System.EventArgs! e) -> void
 static System.Windows.Forms.Application.SetColorMode(System.Windows.Forms.SystemColorMode systemColorMode) -> void
 static System.Windows.Forms.TaskDialog.ShowDialogAsync(nint hwndOwner, System.Windows.Forms.TaskDialogPage! page, System.Windows.Forms.TaskDialogStartupLocation startupLocation = System.Windows.Forms.TaskDialogStartupLocation.CenterOwner) -> System.Threading.Tasks.Task<System.Windows.Forms.TaskDialogButton!>!
 static System.Windows.Forms.TaskDialog.ShowDialogAsync(System.Windows.Forms.IWin32Window! owner, System.Windows.Forms.TaskDialogPage! page, System.Windows.Forms.TaskDialogStartupLocation startupLocation = System.Windows.Forms.TaskDialogStartupLocation.CenterOwner) -> System.Threading.Tasks.Task<System.Windows.Forms.TaskDialogButton!>!

src/System.Windows.Forms/System/Windows/Forms/Controls/Buttons/ButtonBase.cs

@@ -1202,6 +1202,23 @@ protected override void OnKeyDown(KeyEventArgs kevent)
         base.OnKeyDown(kevent);
     }
 
+    internal bool BackColorSet { get; set; }
+    internal bool ForeColorSet { get; set; }
+
+    protected override void OnForeColorChanged(EventArgs e)
+    {
+        base.OnForeColorChanged(e);
+        ForeColorSet = ShouldSerializeForeColor();
+        UpdateOwnerDraw();
+    }
+
+    protected override void OnBackColorChanged(EventArgs e)
+    {
+        base.OnBackColorChanged(e);
+        BackColorSet = ShouldSerializeBackColor();
+        UpdateOwnerDraw();
+    }
+
     /// <summary>
     ///  Raises the <see cref="OnKeyUp"/> event.
     /// </summary>

src/System.Windows.Forms/System/Windows/Forms/Controls/Buttons/ButtonInternal/DarkMode/ButtonDarkModeAdapter.cs

@@ -25,6 +25,51 @@ internal ButtonDarkModeAdapter(ButtonBase control) : base(control)
     private ButtonDarkModeRendererBase ButtonDarkModeRenderer =>
         _buttonDarkModeRenderer;
 
+    private Color GetButtonTextColor(IDeviceContext deviceContext, PushButtonState state)
+    {
+        Color textColor;
+
+        if (Control.ForeColorSet)
+        {
+            textColor = new ColorOptions(deviceContext, Control.ForeColor, Control.BackColor)
+            {
+                Enabled = Control.Enabled
+            }.Calculate().WindowText;
+
+            if (IsHighContrastHighlighted())
+            {
+                textColor = SystemColors.HighlightText;
+            }
+        }
+        else
+        {
+            textColor = ButtonDarkModeRenderer.GetTextColor(state, Control.IsDefault);
+        }
+
+        return textColor;
+    }
+
+    private Color GetButtonBackColor(PushButtonState state)
+    {
+        Color textColor;
+
+        if (Control.BackColorSet)
+        {
+            textColor = Control.BackColor;
+
+            if (IsHighContrastHighlighted())
+            {
+                textColor = SystemColors.HighlightText;
+            }
+        }
+        else
+        {
+            textColor = ButtonDarkModeRenderer.GetBackgroundColor(state, Control.IsDefault);
+        }
+
+        return textColor;
+    }
+
     internal override void PaintUp(PaintEventArgs e, CheckState state)
     {
         try
@@ -36,21 +81,23 @@ internal override void PaintUp(PaintEventArgs e, CheckState state)
 
             LayoutData layout = CommonLayout().Layout();
 
+            PushButtonState pushButtonState = ToPushButtonState(state, Control.Enabled);
             ButtonDarkModeRenderer.RenderButton(
                 g,
                 Control.ClientRectangle,
                 Control.FlatStyle,
-                ToPushButtonState(state, Control.Enabled),
+                pushButtonState,
                 Control.IsDefault,
                 Control.Focused,
                 Control.ShowFocusCues,
                 Control.Parent?.BackColor ?? Control.BackColor,
+                GetButtonBackColor(pushButtonState),
                 _ => PaintImage(e, layout),
-                (_, textColor, drawFocus) => PaintField(
+                () => PaintField(
                     e,
                     layout,
                     PaintDarkModeRender(e).Calculate(),
-                    textColor,
+                    GetButtonTextColor(e, pushButtonState),
                     drawFocus: false)
             );
 
@@ -82,12 +129,13 @@ internal override void PaintDown(PaintEventArgs e, CheckState state)
                 Control.Focused,
                 Control.ShowFocusCues,
                 Control.Parent?.BackColor ?? Control.BackColor,
+                GetButtonBackColor(PushButtonState.Pressed),
                 _ => PaintImage(e, layout),
-                (_, textColor, drawFocus) => PaintField(
+                () => PaintField(
                     e,
                     layout,
                     PaintDarkModeRender(e).Calculate(),
-                    textColor,
+                    GetButtonTextColor(e, PushButtonState.Pressed),
                     drawFocus: false)
             );
 
@@ -119,12 +167,13 @@ internal override void PaintOver(PaintEventArgs e, CheckState state)
                 Control.Focused,
                 Control.ShowFocusCues,
                 Control.Parent?.BackColor ?? Control.BackColor,
+                GetButtonBackColor(PushButtonState.Hot),
                 _ => PaintImage(e, layout),
-                (_, textColor, drawFocus) => PaintField(
+                () => PaintField(
                     e,
                     layout,
                     PaintDarkModeRender(e).Calculate(),
-                    textColor,
+                    GetButtonTextColor(e, PushButtonState.Hot),
                     drawFocus: false)
             );
 

src/System.Windows.Forms/System/Windows/Forms/Controls/Buttons/ButtonInternal/DarkMode/ButtonDarkModeRendererBase.cs

@@ -37,8 +37,9 @@ public void RenderButton(
         bool focused,
         bool showFocusCues,
         Color parentBackgroundColor,
+        Color backColor,
         Action<Rectangle> paintImage,
-        Action<Rectangle, Color, bool> paintField)
+        Action paintField)
     {
         ArgumentNullException.ThrowIfNull(graphics);
         ArgumentNullException.ThrowIfNull(paintImage);
@@ -60,15 +61,12 @@ public void RenderButton(
                 height: bounds.Height - padding.Vertical);
 
             // Draw button background and get content bounds
-            Rectangle contentBounds = DrawButtonBackground(graphics, paddedBounds, state, isDefault);
+            Rectangle contentBounds = DrawButtonBackground(graphics, paddedBounds, state, isDefault, backColor);
 
             // Paint image and field using the provided delegates
             paintImage(contentBounds);
 
-            paintField(
-                contentBounds,
-                GetTextColor(state, isDefault),
-                false);
+            paintField();
 
             if (focused && showFocusCues)
             {
@@ -78,9 +76,11 @@ public void RenderButton(
         }
     }
 
-    public abstract Rectangle DrawButtonBackground(Graphics graphics, Rectangle bounds, PushButtonState state, bool isDefault);
+    public abstract Rectangle DrawButtonBackground(Graphics graphics, Rectangle bounds, PushButtonState state, bool isDefault, Color backColor);
 
     public abstract void DrawFocusIndicator(Graphics graphics, Rectangle contentBounds, bool isDefault);
 
     public abstract Color GetTextColor(PushButtonState state, bool isDefault);
+
+    public abstract Color GetBackgroundColor(PushButtonState state, bool isDefault);
 }

src/System.Windows.Forms/System/Windows/Forms/Controls/Buttons/ButtonInternal/DarkMode/FlatButtonDarkModeRenderer.cs

@@ -23,10 +23,10 @@ internal sealed class FlatButtonDarkModeRenderer : ButtonDarkModeRendererBase
     private protected override Padding PaddingCore { get; } = new(0);
 
     public override Rectangle DrawButtonBackground(
-        Graphics graphics, Rectangle bounds, PushButtonState state, bool isDefault)
+        Graphics graphics, Rectangle bounds, PushButtonState state, bool isDefault, Color backColor)
     {
         // fill background
-        using var back = GetBackgroundColor(state, isDefault).GetCachedSolidBrushScope();
+        using var back = backColor.GetCachedSolidBrushScope();
         graphics.FillRectangle(back, bounds);
 
         // draw border identical to Win32
@@ -58,7 +58,7 @@ public override Color GetTextColor(PushButtonState state, bool isDefault) =>
                 ? DefaultColors.AcceptButtonTextColor
                 : DefaultColors.NormalTextColor;
 
-    private static Color GetBackgroundColor(PushButtonState state, bool isDefault) =>
+    public override Color GetBackgroundColor(PushButtonState state, bool isDefault) =>
         isDefault
             ? state switch
             {

src/System.Windows.Forms/System/Windows/Forms/Controls/Buttons/ButtonInternal/DarkMode/IButtonRenderer.cs

@@ -48,8 +48,9 @@ void RenderButton(
         bool focused,
         bool showFocusCues,
         Color parentBackgroundColor,
+        Color backColor,
         Action<Rectangle> paintImage,
-        Action<Rectangle, Color, bool> paintField);
+        Action paintField);
 
     /// <summary>
     ///  Draws button background with appropriate styling.
@@ -59,7 +60,7 @@ void RenderButton(
     /// <param name="state">State of the button (normal, hot, pressed, disabled)</param>
     /// <param name="isDefault">True if button is the default button</param>
     /// <returns>The content bounds (area inside the button for text/image)</returns>
-    Rectangle DrawButtonBackground(Graphics graphics, Rectangle bounds, PushButtonState state, bool isDefault);
+    Rectangle DrawButtonBackground(Graphics graphics, Rectangle bounds, PushButtonState state, bool isDefault, Color backColor);
 
     /// <summary>
     ///  Draws focus indicator appropriate for this style.

src/System.Windows.Forms/System/Windows/Forms/Controls/Buttons/ButtonInternal/DarkMode/PopupButtonDarkModeRenderer.cs

@@ -30,7 +30,7 @@ internal class PopupButtonDarkModeRenderer : ButtonDarkModeRendererBase
     /// <summary>
     ///  Draws button background with popup styling, including subtle 3D effect.
     /// </summary>
-    public override Rectangle DrawButtonBackground(Graphics graphics, Rectangle bounds, PushButtonState state, bool isDefault)
+    public override Rectangle DrawButtonBackground(Graphics graphics, Rectangle bounds, PushButtonState state, bool isDefault, Color backColor)
     {
         // Use padding from ButtonDarkModeRenderer
         Padding padding = PaddingCore;
@@ -45,9 +45,6 @@ public override Rectangle DrawButtonBackground(Graphics graphics, Rectangle boun
             contentBounds.Offset(ContentOffset, ContentOffset);
         }
 
-        // Get appropriate background color based on state
-        Color backColor = GetBackgroundColor(state, isDefault);
-
         // Create path for rounded corners
         using GraphicsPath path = CreateRoundedRectanglePath(paddedBounds, ButtonCornerRadius);
 
@@ -101,7 +98,7 @@ public override Color GetTextColor(PushButtonState state, bool isDefault) =>
     /// <summary>
     ///  Gets the background color appropriate for the button state and type.
     /// </summary>
-    private static Color GetBackgroundColor(PushButtonState state, bool isDefault) =>
+    public override Color GetBackgroundColor(PushButtonState state, bool isDefault) =>
         isDefault
             ? state switch
             {

src/System.Windows.Forms/System/Windows/Forms/Controls/Buttons/ButtonInternal/DarkMode/SystemButtonDarkModeRenderer.cs

@@ -30,16 +30,13 @@ internal class SystemButtonDarkModeRenderer : ButtonDarkModeRendererBase
     /// <summary>
     ///  Draws button background with system styling (larger rounded corners).
     /// </summary>
-    public override Rectangle DrawButtonBackground(Graphics graphics, Rectangle bounds, PushButtonState state, bool isDefault)
+    public override Rectangle DrawButtonBackground(Graphics graphics, Rectangle bounds, PushButtonState state, bool isDefault, Color backColor)
     {
         // Shrink for DarkBorderGap and FocusBorderThickness
         Rectangle fillBounds = Rectangle.Inflate(bounds, -SystemStylePadding, -SystemStylePadding);
 
         using GraphicsPath fillPath = CreateRoundedRectanglePath(fillBounds, CornerRadius - DarkBorderGapThickness);
 
-        // Get appropriate background color based on state
-        Color backColor = GetBackgroundColor(state, isDefault);
-
         // Fill the background using cached brush
         using var brush = backColor.GetCachedSolidBrushScope();
         graphics.FillPath(brush, fillPath);
@@ -82,7 +79,7 @@ public override Color GetTextColor(PushButtonState state, bool isDefault) =>
     /// <summary>
     ///  Gets the background color appropriate for the button state and type.
     /// </summary>
-    private static Color GetBackgroundColor(PushButtonState state, bool isDefault) =>
+    public override Color GetBackgroundColor(PushButtonState state, bool isDefault) =>
         // For default button in System style, use a darker version of the background color
         isDefault
             ? state switch
@@ -114,7 +111,7 @@ private static Color GetBackgroundColor(PushButtonState state, bool isDefault) =
     /// <summary>
     ///  Draws the button border based on the current state, using anti-aliasing and an additional inner border.
     /// </summary>
-    public static void DrawButtonBorder(
+    public void DrawButtonBorder(
         Graphics graphics,
         Rectangle bounds,
         PushButtonState state,