They have... I mean you mixed it up a little, but nothing unforgivable or... really nothing that's not ignorable. In general the way the Drow territory is set up is that the Drow of each region physically represent their region and the god they worship... whether that be red hair for the underground/volcano/cave dwelling drow, or blue toned hair for the mountain peak/outdoor/ice dwelling drow. So technically those guys should have had red hair... but that's the only thing that really makes any difference... and like I said... the difference is totally negligible. Their eyes (like Soza's) are kinda glossed over and reflective to adjust to the darkness in both regions. The ice drow are technically outside, but they live in a land of black jagged mountains and perpetual thick dark cloud cover.