fix update of link text color in highlighting editor

src/AddIns/DisplayBindings/AvalonEdit.AddIn/Src/CustomizableHighlightingColorizer.cs

@@ -40,6 +40,8 @@ namespace ICSharpCode.AvalonEdit.AddIn
 			textEditor.TextArea.ClearValue(TextArea.SelectionBrushProperty);
 			textEditor.TextArea.ClearValue(TextArea.SelectionForegroundProperty);
 			textEditor.TextArea.TextView.ClearValue(TextView.NonPrintableCharacterBrushProperty);
+			textEditor.TextArea.TextView.ClearValue(TextView.LinkTextForegroundBrushProperty);
+			textEditor.TextArea.TextView.ClearValue(TextView.LinkTextBackgroundBrushProperty);
 			
 			// 'assigned' flags are used so that the first matching customization wins.
 			// This is necessary because more specific customizations come first in the list

src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Rendering/TextView.cs

@@ -1907,7 +1907,9 @@ namespace ICSharpCode.AvalonEdit.Rendering
 				// and we need to re-measure the font metrics:
 				InvalidateDefaultTextMetrics();
 			} else if (e.Property == Control.ForegroundProperty
-			           || e.Property == TextView.NonPrintableCharacterBrushProperty)
+			           || e.Property == TextView.NonPrintableCharacterBrushProperty
+			           || e.Property == TextView.LinkTextBackgroundBrushProperty
+			           || e.Property == TextView.LinkTextForegroundBrushProperty)
 			{
 				// changing brushes requires recreating the cached elements
 				RecreateCachedElements();