[flexcoders] ToggleButtonBar - how to change color for only one button

[isa_loyer]

I have a tooglebuttonbar (with 4 buttons) and I'd like to change the color of 
only one or two button according particular data. Is someone has experience to 
do that.

I try to do like that

 var child:Button;
   child = Button(tbbAction2.getChildAt(0));
child.setStyle('color', '#CC33CC');
But there's no effect. Thanks a lot.