var AColorTransform = {ra:100, rb:255, ga:100, gb:255, ba:100, bb:255, aa:100, ab:255};
var myColor = new Color(mc);
myColor.setTransform(AColorTransform);

var myColor = new Color(mc);
//set to black
myColor.setRGB(0x000000);
//or set to white
myColor.setRGB(0xFFFFFF);

a (multiplier 0 > 100%)   b(offset -255 > 255)
r       ra                       rb

g       ga                       gb

b       ba                       bb

a       aa                       bb

r (result red color) = (RR * ra%) + rb
g (result green color) = (GG * ga%) + gb
b (result blue color) = (BB * ba%) + bb
a (result alpha) = (AA * aa%) + ab