Colored gear with specific classes.

[Kiote]

With some classes the uniqueness comes from the role you choose to play. Either way, at least now I'll know whether this person I am looking at is a healer or a nuker/enfeebler. When before, there was no way to tell.

Once again, aesthetical uniqueness is there.

Um, no because the stats granted by a color are in no way specific to that color. One green robe might offer mind another green robe might offer int. Its different on every item.