On the old white MacBooks I personally liked the yellowing underneath where my wrists sat. It said to the world "hey, this guy is spending WAY too much time online and may have some hygiene issues he needs to work out."
Guh, those were some of the absolute shittiest portables Apple ever put out. Even after the discoloring plasticizers were worked out, almost every single one of them saw the topcase flake and crack in normal use. Performance was poor out of the box, the screens were garbage, and the bottom looked bad after only moderate use.
