The great thing about OBP is that anything will go with it. Check out all the wheel and photo threads and find the look you like... stealth, bling, simple, etc. If you like a more aggressive look, I think a darker color is better, say black, dark gray or dark bronze. If you are going for a simple and clean look, stick with a regular gold or silver.
My favorite is OBP with Black or a titanium or dark gray!