My MG has the factory OEM wheels and they are mostly black with silver-painted accents on them. Black wheels go back a long time.
My preferences on color vary a whole lot. By and large, I'm a big fan of OEM rims. In fact, not too long ago I was looking at a Jag S-type R that was priced fairly but had some terrible looking aftermarket chrome. They were at least in the OEM diameter and had nice OEM sized Michelins on them, so I could have bought a set of factory rims without worrying about tires. The problem, though, was that I found I'd be looking at HUGE bill to find OEM S-type R rims-they seem to make their way onto a lot of non-R S-types. The brakes on the R mean that you MUST have an 18" rim(or larger) so AFAIK the real R rims are the only factory option. The rims made an okay deal into a terrible deal for me(especially when I started considering how bad repairs were going to be on a 100K+ sueprcharged Jag, even though I know the engine well in NA form).
All of that aside, I actually tend to shy away from chrome unless the wheel is a fairly simple design. Someone posted a photo of a 'Vette earlier in this thread with a thin 5-spoke design in chrome-that to me is a great looking chrome wheel. If the design starts getting very complicated, I much prefer more of a matte finish whatever form that takes(anodized aluminum, etc). I like light gray on some cars, but don't care for anything much darker than that.