Blood Elves skin colours are unique only to the Horde, but they are not unique to the entire game with Humans, Dwarves and Gnomes also having those skin options. On top of that, the blue ares are also not unique to the Blood Elves, considering it has been shown on Alliance High Elven NPC's, which the exception of a couple, but even with those, there eyes are like the old DK's eyes.