I repaired one of my wheels. I went to a local auto paint supplier with my wheel and chose a paint that matched. They had a book of what they called fleet colors that they sell in bulk, and there was a silver in it that was a very good match for my wheels. It was much cheaper than most auto paints. It was a base coat-clear coat system, so a decent spray gun is a necessity. They didn't have a proper label for it but the writing on the can says Omni AU Bright Silver Metallic. Maybe that will give you somewhere to start.