Add three-state color resolution to TableControl

null = inherit from container, Color.Default = use theme (default),
explicit color = use as-is. Fixes WithBackgroundColor(null) not
inheriting container background. Builder color params now accept
nullable Color?.

Author: nickprotop

SharpConsoleUI/Builders/TableControlBuilder.cs

@@ -26,8 +26,8 @@ public sealed class TableControlBuilder
 	private readonly List<TableRow> _rows = new();
 	private BorderStyle _borderStyle = BorderStyle.Single;
 	private Color? _borderColor;
-	private Color? _headerBackgroundColor;
-	private Color? _headerForegroundColor;
+	private Color? _headerBackgroundColor = Color.Default;
+	private Color? _headerForegroundColor = Color.Default;
 	private bool _showHeader = true;
 	private bool _showRowSeparators = false;
 	private bool _useSafeBorder = false;
@@ -44,8 +44,8 @@ public sealed class TableControlBuilder
 	private string? _name;
 	private object? _tag;
 	private StickyPosition _stickyPosition = StickyPosition.None;
-	private Color? _backgroundColor;
-	private Color? _foregroundColor;
+	private Color? _backgroundColor = Color.Default;
+	private Color? _foregroundColor = Color.Default;
 
 	#region Column Configuration
 
@@ -387,25 +387,25 @@ public TableControlBuilder StickyBottom()
 	/// <summary>
 	/// Sets the background color.
 	/// </summary>
-	public TableControlBuilder WithBackgroundColor(Color color)
+	public TableControlBuilder WithBackgroundColor(Color? color)
 	{
 		_backgroundColor = color;
 		return this;
 	}
 
 	/// <summary>
-	/// Sets the foreground (text) color.
+	/// Sets the foreground (text) color. Pass null to inherit from container.
 	/// </summary>
-	public TableControlBuilder WithForegroundColor(Color color)
+	public TableControlBuilder WithForegroundColor(Color? color)
 	{
 		_foregroundColor = color;
 		return this;
 	}
 
 	/// <summary>
-	/// Sets both foreground and background colors.
+	/// Sets both foreground and background colors. Pass null to inherit from container.
 	/// </summary>
-	public TableControlBuilder WithColors(Color foreground, Color background)
+	public TableControlBuilder WithColors(Color? foreground, Color? background)
 	{
 		_foregroundColor = foreground;
 		_backgroundColor = background;

SharpConsoleUI/Controls/TableControl.cs

@@ -30,8 +30,8 @@ public class TableControl : IWindowControl, IDOMPaintable, IMouseAwareControl
 
 	private HorizontalAlignment _horizontalAlignment = HorizontalAlignment.Left;
 	private VerticalAlignment _verticalAlignment = VerticalAlignment.Top;
-	private Color? _backgroundColorValue;
-	private Color? _foregroundColorValue;
+	private Color? _backgroundColorValue = Color.Default;
+	private Color? _foregroundColorValue = Color.Default;
 	private Margin _margin = new Margin(0, 0, 0, 0);
 	private StickyPosition _stickyPosition = StickyPosition.None;
 	private bool _visible = true;
@@ -43,8 +43,8 @@ public class TableControl : IWindowControl, IDOMPaintable, IMouseAwareControl
 	private List<TableRow> _rows = new();
 	private BorderStyle _borderStyle = BorderStyle.Single;
 	private Color? _borderColorValue;
-	private Color? _headerBackgroundColorValue;
-	private Color? _headerForegroundColorValue;
+	private Color? _headerBackgroundColorValue = Color.Default;
+	private Color? _headerForegroundColorValue = Color.Default;
 	private bool _showHeader = true;
 	private bool _showRowSeparators = false;
 	private bool _useSafeBorder = false;
@@ -485,41 +485,66 @@ public void SetData(IEnumerable<TableRow> rows)
 
 	#region Color Resolution Methods
 
+	/// <summary>
+	/// Three-state resolution: null = inherit from container,
+	/// Color.Default = use theme, explicit color = use as-is.
+	/// </summary>
 	private Color ResolveBackgroundColor(Color defaultBg)
 	{
-		var theme = Container?.GetConsoleWindowSystem?.Theme;
-		return _backgroundColorValue
-			?? theme?.TableBackgroundColor
-			?? Container?.BackgroundColor
-			?? defaultBg;
+		if (_backgroundColorValue == null)
+			return Container?.BackgroundColor ?? defaultBg;
+		if (_backgroundColorValue.Value == Color.Default)
+		{
+			var theme = Container?.GetConsoleWindowSystem?.Theme;
+			return theme?.TableBackgroundColor
+				?? Container?.BackgroundColor
+				?? defaultBg;
+		}
+		return _backgroundColorValue.Value;
 	}
 
 	private Color ResolveForegroundColor(Color defaultFg)
 	{
-		var theme = Container?.GetConsoleWindowSystem?.Theme;
-		return _foregroundColorValue
-			?? theme?.TableForegroundColor
-			?? Container?.ForegroundColor
-			?? defaultFg;
+		if (_foregroundColorValue == null)
+			return Container?.ForegroundColor ?? defaultFg;
+		if (_foregroundColorValue.Value == Color.Default)
+		{
+			var theme = Container?.GetConsoleWindowSystem?.Theme;
+			return theme?.TableForegroundColor
+				?? Container?.ForegroundColor
+				?? defaultFg;
+		}
+		return _foregroundColorValue.Value;
 	}
 
 	private Color ResolveHeaderBackgroundColor()
 	{
-		var theme = Container?.GetConsoleWindowSystem?.Theme;
-		return _headerBackgroundColorValue
-			?? theme?.TableHeaderBackgroundColor
-			?? theme?.TableBackgroundColor
-			?? Container?.BackgroundColor
-			?? Color.Black;
+		if (_headerBackgroundColorValue == null)
+			return Container?.BackgroundColor ?? Color.Black;
+		if (_headerBackgroundColorValue.Value == Color.Default)
+		{
+			var theme = Container?.GetConsoleWindowSystem?.Theme;
+			return theme?.TableHeaderBackgroundColor
+				?? theme?.TableBackgroundColor
+				?? Container?.BackgroundColor
+				?? Color.Black;
+		}
+		return _headerBackgroundColorValue.Value;
 	}
 
 	private Color ResolveHeaderForegroundColor()
 	{
-		var theme = Container?.GetConsoleWindowSystem?.Theme;
-		return _headerForegroundColorValue
-			?? theme?.TableHeaderForegroundColor
-			?? theme?.TableForegroundColor
-			?? Color.White;
+		if (_headerForegroundColorValue == null)
+			return Container?.ForegroundColor ?? Color.White;
+		if (_headerForegroundColorValue.Value == Color.Default)
+		{
+			var theme = Container?.GetConsoleWindowSystem?.Theme;
+			return theme?.TableHeaderForegroundColor
+				?? theme?.TableForegroundColor
+				?? Container?.ForegroundColor
+				?? Color.White;
+		}
+		return _headerForegroundColorValue.Value;
 	}
 
 	private Color ResolveBorderColor()