Color schemes - unit test fixes

UnitTests/View/Layout/Dim.Tests.cs

@@ -224,6 +224,9 @@ public class DimTests
     [AutoInitShutdown]
     public void Only_DimAbsolute_And_DimFactor_As_A_Different_Procedure_For_Assigning_Value_To_Width_Or_Height ()
     {
+        // Override CM
+        Button.DefaultShadow = ShadowStyle.None;
+
         // Testing with the Button because it properly handles the Dim class.
         Toplevel t = new ();
 

UnitTests/View/Layout/Pos.AnchorEndTests.cs

@@ -177,6 +177,9 @@ public class PosAnchorEndTests (ITestOutputHelper output)
     {
         ((FakeDriver)Application.Driver!).SetBufferSize (20, 5);
 
+        // Override CM
+        Button.DefaultShadow = ShadowStyle.None;
+        
         var b = $"{CM.Glyphs.LeftBracket} Ok {CM.Glyphs.RightBracket}";
 
         var frame = new FrameView { Width = 18, Height = 3 };