I know this post is rather old, but I finally came around to buying an 360, and a month after I came around to spray painting it. Me and my brother finished mine today, just need to put it back together, but in the mean time, here is a mock-up.
I will have more pictures posted tomorrow of the progress of his controller, and my finished product. *note: the bottom silver part, which is not well seen in the pictures, is also painted the metallic cyan of the shoulder buttons, and the cyan paint looks better in real life, with it's metallic sheen.