Wax your wiper arms.
I was waxing the car the other day, and while hitting the hood, I got some wax on one of my wiper arms. When waxing, ive always instictively avoided black stuff. Crap. Well, not crap after all. Mine were a touch faded and I was considering getting new ones. The spot I wiped the wax from looked great. I did the rest of the arms and they look as good as new. I seems simple, but if yours are faded, give it a shot.