To my mind, it would be logical if the Drow were all albino, as many cave-dwelling creatures are. In my comic Corner Alley 13 ( [link] ) however, they have their traditional appearance with dark skin and red eyes, i.e occular albinism.
In this picture I have also given the Drow girl large, bat-like ears as I assumed that her hearing would need to be excellent in such dark surroundings. She may even be blind. I postulate this with the assumption that the Drow, after thousands of years in the Underdark, cut off from the Surface, would adapt to their environment.

Disagree? I most heartily encourage discussion on this subject!

Further comment: Thank you for some great discussions on this subject! Some of the comments contained points so important that they ought to be mentioned here.
1) Talking of evolution in this context in misleading, as the process takes a lot longer than the few thousand years I am talking about. This becomes even more true if one assumes that the Drow have a longer life-span and reach maturity later than Humans.
2) A self-contained world COMPLETELY without sunlight is not orthodox D&D, whichever version of the rules one looks at. I know this and I only discuss the make-up of life without sunlight because it is an amusing theoretical dilemma.
3) There are several different versions of the D&D world. In one early version, the Drow were in fact pale.