I recently painted some of my 22.5" wheels, I had them sandblasted then I used PPG epoxy primer in medium grey, color coat is PPG acrylic urethane in black, two medium coats and completely covered the grey.

1957 Chevrolet 5700 LCF 283 SM420 2 speed rear, 1955 IH 300U T/A, 1978 Corvette 350 auto, 1978 Yamaha DT175, 1999 Harley Davidson Softail Fat Boy