Other BMW wheels use a combined process for that 'chrome/silver/smoked' look:

First black is powder coated, THEN a layer of silver is painted on- this is a semi-translucent layer, the about of silver paint determines the color. Then they are clearcoated.

This is the process on the E39M5 wheels. There are a few shops that can do this, but pricing is $200 is per.

Every 'color' I've seen, as in a 'full color coat' will miss the mark on this look. There is no 'color code'.

GL

A