Changing simple button color

Question

It would seem as if this would be simple, but I'm not finding
any documentation.
I have a map of the US. Each U.S. state is a simple button.
I'd like to change the button fill color (and potentially, the
outline color) in AS3. I've created the buttons in Flash, not in
AS3 (just graphically). How do I change the button fill color?
Sample code:
function addButtonListeners(btnInstance:SimpleButton) {
btnInstance.addEventListener( MouseEvent.ROLL_OVER,
handleRollover);
btnInstance.addEventListener( MouseEvent.ROLL_OUT,
handleRollover);
addButtonListeners(Montana);
addButtonListeners(NewMexico);
addButtonListeners(Washington);
Montana._color = 0xA6CsDA; //doesn't work

Answer 1

I also tried this code, but I'm getting the error message:
Access of possibly undefined property rgb through a reference
with static type flash.geom:ColorTransform.
Source: color.rgb = 0x00ff00;