As an intro to User Controls, I'm trying to create an LED User Control. When adding the LEDControl to my xaml, I want to be able to specify the color of the LED, LEDColor. I've added two storyboards to the LED, TurnOn, and TurnOff, that animate the Rectangle fill color between 'off' (grey) and 'on' (LEDColor).

**How do I dynamically specify the color that the the storyboard will use for the 'To' value?**

Note, I am using Silverlight for Windows Phone. At this point, I'm targetting wp7 but open to Mango soltions if it makes it more sense.