As AspenDog has stated. Working with a one-piece wheel is difficult. There is ethching primer and like RIM1 stated a primer for Chrome.
I have had all of my wheels painted and not had any problems.
If you have a 2 or 3 piece wheel. I would break the wheel down, so the centers can be stripped, if they are chrome, to get to the bare metal and then primer and paint.
I recently took my 2 piece wheels apart and I am having the centers painted in Silver Steel Metallic. Granted my centers are already painted Black. If they were chrome I would have had them stripped down to the bare metal, then primer and paint.
