There's a number of places that do these repairs. Haven't had to try any yet but there might be one of these that you want to look into...

www.rimdoc.com
www.transwheel.com
www.wheelcollision.com
www.wheelsamerica.com

I'm assuming that you'll change your wheels in the winter. That would be the time to look at doing any repairs.

OR you could do a quick paint job yourself
Wurth Silver Wheel Spray Paint