Not 100% sure, but I think the process ends with a paint coat (any color) and clear powder coat baked over that. I had it done to the stock wheels on my Mustang for $100/wheel. I had them keep the bare metal around the outer edge (the transition is razor sharp) and they came out looking like they were made that way. It took about 5 or 6 hours from start to finish including them removing the wheels/tires, balance & re-installation. Google "wheel restoration" in your city.