wpf storyboard results high cpu

Question

Hi all

I'm using few storyboards in my application in the style of few controls, the storybards use to flash the control when appears on screen, the problem is that from the first control appear the cpu usage gets to 50% I added Timeline.DesiredFrameRate="20" to the storyboards with no use

is there any solution to this problem or at least someone can explain me what cause it (software, hardware or both?)

those are my color animation in use:

ColorAnimation Storyboard.TargetProperty="Background.Color"  FillBehavior="Stop" RepeatBehavior="Forever"  From="Red" To="White" Duration="0:0:1"   

Thanks Eran