I've been doing some research on options for replicating the Dow-7 coating used on magnesium wheels. I haven't had much luck in finding a specific brand/color to paint the wheels for my project. Part of the issue is that the real coating doesn't last very long and will darken as it ages from a greenish/gold to the gray.
Here is something I came up with last night. Its basically just a 50/50 mix of Testors Gold and Flat Green although I feel a touch of gray to darken it might have helped.