Fill = Brushes.Red
<Window x:Class="WpfApplication1.Window1" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" Title="" Height="300" Width="300"> <Canvas> <TextBlock Text="Predefined Brush [ .Fill = Brushes.Red; ]"/> <Rectangle HorizontalAlignment="Left" Width="60" Height="20" Fill="Red"/> </Canvas> </Window>