Fix DarkMode (a) StatusStrip background renderer A11Y Regression.

.github/copilot-instructions.md

@@ -423,6 +423,16 @@ using Pen focusPen = new(focusColor) // Use 'using' with type name and omit type
 
 - **Don't XML-comment local functions**, as this is not supported. Instead, be more verbose in a comment if the local function's purpose is not immediately obvious.
 
+- **Use `<inheritdoc/>` for inherited members** to avoid duplication and ensure consistency in documentation.
+  ```csharp
+  /// <inheritdoc/>
+  public override void OnClick(EventArgs e)
+  {
+      base.OnClick(e);
+      // Additional logic here
+  }
+  ```
+
 ### 1.9 File Structure and Formatting
 
 - **Use file-scoped namespaces**

src/System.Windows.Forms/System/Windows/Forms/Controls/ToolStrips/StatusStrip.cs

@@ -118,7 +118,7 @@ public override DockStyle Dock
         set => base.LayoutStyle = value;
     }
 
-    // we do some custom stuff with padding to accomodate size grip.
+    // we do some custom stuff with padding to accommodate size grip.
     // changing this is not supported at DT
     [Browsable(false)]
     public new Padding Padding

src/System.Windows.Forms/System/Windows/Forms/Controls/ToolStrips/ToolStrip.cs

@@ -1549,7 +1549,7 @@ public ToolStripRenderMode RenderMode
                 return ToolStripRenderMode.ManagerRenderMode;
             }
 
-            if (_renderer is not null && !_renderer.IsAutoGenerated)
+            if (_renderer is not null && !_renderer.IsSystemDefaultAlternative)
             {
                 return ToolStripRenderMode.Custom;
             }
@@ -3250,7 +3250,7 @@ protected override void OnLayout(LayoutEventArgs e)
     {
         LayoutRequired = false;
 
-        // we need to do this to prevent autosizing to happen while we're reparenting.
+        // we need to do this to prevent auto-sizing to happen while we're reparenting.
         ToolStripOverflow? overflow = GetOverflow();
         if (overflow is not null)
         {
@@ -3636,6 +3636,7 @@ protected override void OnPaintBackground(PaintEventArgs e)
 
         Graphics g = e.GraphicsInternal;
         GraphicsState graphicsState = g.Save();
+
         try
         {
             using (Region? transparentRegion = Renderer.GetTransparentRegion(this))
@@ -3647,6 +3648,12 @@ protected override void OnPaintBackground(PaintEventArgs e)
                 }
             }
 
+            if (Renderer.RendererOverride is ToolStripRenderer renderer)
+            {
+                renderer.DrawToolStripBackground(new ToolStripRenderEventArgs(g, this));
+                return;
+            }
+
             Renderer.DrawToolStripBackground(new ToolStripRenderEventArgs(g, this));
         }
         finally

src/System.Windows.Forms/System/Windows/Forms/Controls/ToolStrips/ToolStripManager.cs

@@ -489,7 +489,7 @@ public static ToolStripManagerRenderMode RenderMode
         {
             Type currentType = CurrentRendererType;
 
-            if (t_defaultRenderer is not null && !t_defaultRenderer.IsAutoGenerated)
+            if (t_defaultRenderer is not null && !t_defaultRenderer.IsSystemDefaultAlternative)
             {
                 return ToolStripManagerRenderMode.Custom;
             }
@@ -546,24 +546,12 @@ public static bool VisualStylesEnabled
 
     internal static ToolStripRenderer CreateRenderer(ToolStripManagerRenderMode renderMode)
     {
-        switch (renderMode)
+        return renderMode switch
         {
-            case ToolStripManagerRenderMode.System:
-                return new ToolStripSystemRenderer(isDefault: true);
-            case ToolStripManagerRenderMode.Professional:
-#pragma warning disable WFO5001 // Type is for evaluation purposes only and is subject to change or removal in future updates. Suppress this diagnostic to proceed.
-                if (Application.IsDarkModeEnabled)
-                {
-                    return new ToolStripProfessionalRenderer(new DarkProfessionalColors());
-                }
-#pragma warning restore WFO5001
-
-                return new ToolStripProfessionalRenderer(isDefault: true);
-
-            case ToolStripManagerRenderMode.Custom:
-            default:
-                return new ToolStripSystemRenderer(isDefault: true);
-        }
+            ToolStripManagerRenderMode.System => new ToolStripSystemRenderer(isDefault: true),
+            ToolStripManagerRenderMode.Professional => new ToolStripProfessionalRenderer(isDefault: true),
+            _ => new ToolStripSystemRenderer(isDefault: true),
+        };
     }
 
     internal static ToolStripRenderer CreateRenderer(ToolStripRenderMode renderMode)