So I went to international site and the 260M wheels looked silver, despite the german, uk, and australian site looking dark. I wrote back to BMW and got the following reply.
Originally Posted by BMW Owners' Circle
I have checked with our wheel specialist and he indicates that the European wheels are slightly different. They are not available on the US models. I am sorry for any inconvenience this may cause.
If you have any further questions, please respond to this e-mail or contact the Customer Relations and Services Department at 1-800-831-1117, Monday through Friday from 9:00 A.M. to 9:00 P.M., Eastern Standard Time. Again, thank you for contacting BMW.
Customer Relations and Services
So, it looks like I'll have to trade with someone in Europe or get mine powdercoated.