Just a short simple suggestion.
I think it would be nice if players could invert two different dyes they are wearing.
Like for example, if I really liked the colors red and blue, and I wanted to see what they looked like on my armor if they were swapped, it would be nice to have that capability.
This is just one minor thing that would make Guild Wars 2 a little nicer in my opinion (especially for me considering I am constantly changing my dyes). (: