Update MainWindow.axaml

samples/AvaloniaDemo/MainWindow.axaml

@@ -98,7 +98,7 @@
                                 EnableConstrains="False"
                                 Background="SlateBlue" ClipToBounds="True" Focusable="True"
                                 VerticalAlignment="Stretch" HorizontalAlignment="Stretch">
-                    <Border Background="WhiteSmoke" BorderBrush="Yellow" BorderThickness="10">
+                    <Border Background="Gray" BorderBrush="Yellow" BorderThickness="10">
                         <Canvas Background="LightGray" Width="300" Height="300">
                             <Rectangle Canvas.Left="100" Canvas.Top="100" Width="50" Height="50" Fill="Red"/>
                             <StackPanel Canvas.Left="100" Canvas.Top="200">