I powder coated my wheels. I have a black 300ZX, my wheels were white. It looked like a hotwheels. I mixed Smoke Chrome and Black Tint in a 1:1 ratio to make Gunmetal thanks to 2003Z advice. I got the perfect color. Before and after pictures will be up tomorrow. I just have to shoot super gloss clear on top.
I really need a sandblaster because getting the white paint off was hard, whoever refinished my wheels initially did a good job. I did a better more tastefull job!