Reset bitmap colorTransform to its original

1

I am trying to reset the state of a bitmap back to its original state
after I transformed its color.



import flash.display.BitmapData;
import flash.geom.ColorTransform;
import flash.geom.Rectangle;
_bmd = BitmapData.loadBitmap("photo");
_mc = this.createEmptyMovieClip("bm_mc", 10);
_mc.attachBitmap(_bmd, 10);
_mc._x = 0;
_mc._y = 0;
_mc.onPress = function() {
    var _ctf = new ColorTransform(1, 1, 1, 1, 0, 0, 100, 0);
       _bmd.colorTransform(_bmd.rectangle, _ctf);
    delete this.onPress;
};

Thank you.