To open, I'm a huge fan of this game. I was also an early-access buyer of Original Sin 1, but both games kinda had a similar problem.
In Original Sin 1, when you got better equipment, it would be... Mismatched. Horribly. This was... [i]Kinda[/i] rectified by the fabric dyes you could get, but they were so damn rare it was practically pointless.
In Original Sin 2, the problem is present and the solution from the first game isn't even present. Which leads to my suggestion.
I would be super appreciative of the ability to select armor colors in-game somehow (Maybe adding some extra options in the character creation menu, or even just in your character sheet panel in the main game). This wouldn't even be overly difficult to do, as you have the ability to select armor colors on characters in the GM Mode, so that could be used as a template for items the player wears.