Animate the background color
<Window x:Class="Main" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" Title="" Height="300" Width="300" Background="Black"> <Window.Triggers> <EventTrigger RoutedEvent="Window.Loaded"> <BeginStoryboard> <Storyboard AutoReverse="True" RepeatBehavior="Forever"> <ColorAnimation Storyboard.TargetProperty="Background.Color" To="White" /> <ColorAnimation Storyboard.TargetName="rect" Storyboard.TargetProperty="(Shape.Fill).(SolidColorBrush.Color)" To="Firebrick" /> </Storyboard> </BeginStoryboard> </EventTrigger> </Window.Triggers> <Rectangle x:Name="rect" Width="100" Height="100" Fill="WhiteSmoke" /> </Window>