One of my wheels was damaged while my car was shipped to me. Called a shop that the local BMW dealership uses and they said that it's actually an anodized finish.
Current: 2008 BMW M3 Sparkling Graphite/Bamboo Beige/6MT. 1999 BMW M3 Techno Violet/Dove/5MT. On the list: BMW M2 Long Beach Blue/Black/6MT