Interesting. I rarely dress my characters according to their class, I do it according to how I designed them and what 'personality' I've associated with them.
You can see my necro in previous posts. She's solid white. I typically keep her in Sylvari T2 cultural (best armor) dyed Celestial. I love that she doesn't look like a necro. Not that I have anything against a necro look, it just amuses me that here's this pure white, angelic looking Sylvari wielding the powers of death. :P
My Asuran thief I have in T2 leather and while I suppose it might look more engineer-esque I like to think that here's this well dressed intellectual that will stun and stab you at any minute. (If you've ever seen a s/d Asura do #3 it is something.)