Set color for SolidColorBrush
<UserControl x:Class='SilverlightApplication3.MainPage' xmlns='http://schemas.microsoft.com/winfx/2006/xaml/presentation' xmlns:x='http://schemas.microsoft.com/winfx/2006/xaml' xmlns:d='http://schemas.microsoft.com/expression/blend/2008' xmlns:mc='http://schemas.openxmlformats.org/markup-compatibility/2006' mc:Ignorable='d' d:DesignWidth='640' d:DesignHeight='480'> <Canvas Background="LightBlue"> <Rectangle Height="50" Width="50" Stroke="Black" StrokeThickness="4" Margin="4"> <Rectangle.Fill> <SolidColorBrush> <SolidColorBrush.Color> <Color A="0" R="111" G="110" B="0"/> </SolidColorBrush.Color> </SolidColorBrush> </Rectangle.Fill> </Rectangle> </Canvas> </UserControl>