Hi all, i'm having a problem with the RGBColor, i can't acces the alpha..

obj.style.fill.color = new RGBColor(0.5,0.5,0.5,0.0);

it's working fine for the color chanel, but the alpha doesn't change ?
in fact it does, cause if i print(obj.style.fill.color);

i get:
{ red: 0.5, green: 0.5, blue: 0.5, alpha: 0.0 }

but on the stage i can't see any differences.
Thanks