I need to rewrite a code made in AS2 to AS3. I have the following code:

import mx.transitions.TweenColorTransform;
import mx.transitions.easing.*;
import flash.geom.ColorTransform;

var tween01 = new TweenColorTransform(
myBall1_mc, // movie clip to tween
"", // property to tween
Strong.easeOut, // easing function
myBall1_mc.transform.colorTransform, // start transform
new ColorTransform(2, 1, 10,0,255,255,255,-255), // final transform
1.5, // seconds duration
true); // use seconds for duration (false = use frames)
// color transform yoyo
tween_ct.onMotionFinished = function()

But when I test this code am getting the following error:

"The class or interface 'mx.transitions.TweenColorTransform' could not be loaded."

Does someone know what I have to do for getting it run properly?
Thank you very much in advance!