Updating my previous post, the outside of my rims are painted body color (408 Havana Brown) and the inside of the rims are all painted black. So it may be safe to say that the wheels come to the assembly plant from the supplier painted black, and the factory painted the outside of the rims to match the body color of the car to which they would be mated during the era when two-piece wheel trim was the norm. Once the one piece full wheel cover was adopted, it was no longer necessary to perform this step, which cost saving likely made the bean-counters very happy indeed!
