ActionScript 3.0 :: Return To Original Gradient Color On Roll Out?

I have a movicelip that has a cirlce with a gradient fill.  When I rollover I use a color transform to change the color.  I'm not sure how to get the color transform to return to its original gradient fill once I roll out of the movieclip
 
var overColor:ColorTransform = new ColorTransform;overColor.color = 0xffcc00;
mc1.addEventListener(MouseEvent.ROLL_OVER, buttonOver);
function buttonOver(e:MouseEvent):void{      mc1.transform.colorTransform = overColor;}