I was at a car show this morning, chatting with a real nice guy a few years older than myself. He volunteered that he preferred silver wheels. I said that I do as well, and that I imagine it's something to do with our age.
"Of course," he said, "We want the wheels to match our hair."
Black only makes sense to me if (a) have them already and don't want to spend money on other wheels, or (2) you don't want anyone's eyes off the rest of the car and know black is the closest you can get to no wheels.