First, it may be good to ensure that your rostyles are structurally sound. A wheel balancing shop will take a look, maybe free of charge, and tell you. At the least, a very close inspection for cracks, anomalies, etc., before you proceed. You don't want a bad wheel to ruin your day.
Perhaps the "best" way is to have the wheels media blasted down to bare metal then primed, painted and clear coated. Moss sells the correct color and I'm sure someone else here will chime in with aftermarket colors that are correct.
A paint mask for the wheels is available, I think Victoria Brit sells them. I've heard varying stories regarding the efffectiveness of these masks.
I hand-sanded the outside of the wheels (didn't do the reverse side), washed thouroughly and cleaned with alcohol, then primed 2 coats with a generic silver metal primer, oversprayed that with 2 coats of rattle can silver, then hand-painted the black parts using a semi-gloss black. They look pretty good but the paint won't last nearly as long as a proper (see above) paint job.
Then, take them to the wheel balancing shop for a good balance job (optional).
It's somewhat of a artsy job getting the black parts right. Took me the best part of 2 days to do mine, but I'm glad I did it.
Anyone else??