Might it be possible to create an armor painting/dyeing item and a paint/dye remover? It could simply open up a window like for your starting armor and let you play with the color of it. Which can be painted/dyed over later if you wish or brought back to the default coloration via a paint/dye remover. If you look around Haven you find multiple people with the exact same armor (5* Wolver series for example) and this would make it so that people with the same armor in parties are more easily distinguishable. Could add a new merchant that sells them, or add them to Boost. About 500 crowns would be a reasonable price for the item I'd think. You could even make variants of it for shields and weapons if you wanted.
~Gwen
If this is technically possible then I would love to see it done...
Then again, considering all armor has certain parts that are set to become your "personal color", I can't imagine that they WOULD have any major technical limits on making the other colors configurable... which is good, because it seems to me that half of the late-tier armor is fire themed, and while red and black works for some people I'm really more of a blue-and-yellow man myself. ;)
And if for some strange reason armor dying IS technically unfeasible, well... then here's to hoping they make a much larger variety of armor available for us to use as costume armor.