Colored gear with specific classes.

[Oscillate_Wildly]

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.

There's no aesthetic uniqueness to having to wear a specific colour.
Why don't you just ask, as everyone else does, for a healer? O:
And you act as though this is going to solve all of your problems, as though everyone is suddenly going to start wearing the piece of armour.
Just determining DD is red, and Tank is Blue isn't uniqueness at all. Especially when every DD is going to resemble the next DD and so on within the same class.

If you want class uniqueness, call for better skills, weapon stances, and purpose. Not a colour scheme.

What I am able to do well as a mage shouldn't depend on the colour of robe I'm wearing or not wearing. It should depend solely on my skills, my choice in weapon, and role I'm asked/want to play.