They are just giving us the same options that pretty much every illustrator has used for just about every book cover with a Drow on it. I mean just look at all the Drizzt's out there...
Jeff Easley got him with Blue-Gray skin
Brom and Lockwood had him Purple
Elmore's got him looking all jaundiced and basically Yellow
There are only a few here and there that go full underdark, but even there its usually when he's got his hood up full body shot heheh.
Jet-Black sounds cool as a descriptor, but doesn't translate all that well visually if you're trying to show the forms in 3 dimensions. Minthara is definitely more purple than ebon here, same deal for the default Drow "Who do you dream of?" first option. I agree though the defaults highlighted when you first open the skin tone screen should probably be a little darker on the color scales for Drow characters.
ps. Justin Sweet had the best run I think IWD2. Those are still among the most popular floating around, and closer to the black you're looking for I think. Still its been going down even in this game when you look at Viconia. In addition to making her more classically attractive in the sequel, they lightened her skin from a dark purple, to a light blue. Just kinda the way it looks now in the popular renderings.
This. I couldn't put it better. Think about graphism and form read. Do you want a character whose skin repel light and make the form a flat black? No.
Also understand that there is no pure black in nature. There are only very dark colours, and at the darkest, absence of light. This is not the same as having a pure, flat black character walking in the sunlight.
