CSS @keyframe in WPF

How would this work? [I'm super new to WPF/XAML]
Edit: Here's a snippit of what I've got

<Image x:Name="loader" Source="loadingicon.png" >
<Image.Clip>
<rectanglegeometry rect="0,0,0,0">
</Image.Clip>
<Image.Triggers>
<eventtrigger routedevent="Image.Loaded">
<eventtrigger.actions>
<beginstoryboard>
<storyboard>
<coloranimationusingkeyframes storyboard.targetproperty="RectangleGeometry.Rect" storyboard.targetname="loader" duration="0:0:6" repeatbehavior="Forever">
<coloranimationusingkeyframes.keyframes>

<!-- Go from green to red in the first 2 seconds. LinearColorKeyFrame creates
a smooth, linear animation between values. -->
<LinearColorKeyFrame Value="Red" KeyTime="0:0:2" />

<!-- In the next half second, go to yellow. DiscreteColorKeyFrame creates a
sudden jump between values. -->
<discretecolorkeyframe value="Yellow" keytime="0:0:2.5">

<!-- In the final 2 seconds of the animation, go from yellow back to green. SplineColorKeyFrame
creates a variable transition between values depending on the KeySpline property. In this example,
the animation starts off slow but toward the end of the time segment, it speeds up exponentially.-->
<splinecolorkeyframe value="Green" keytime="0:0:4.5" keyspline="0.6,0.0 0.9,0.00">


<!--<Image Source="loadingicon.png" />-->




</Image.Triggers>
</Image>

I'm hoping to integrate keyframes the same way in xaml as I do in CSS.