I've actually had this idea myself, and after a little while of troubleshooting I've found not a single major flaw in this.
(So kinda obviously +1 here)
However, my only universal concern with large vanity suggestions is this:
Large games always have a developing team. These devs are constantly working their
off to continually produce game content, fix bugs, etc. Working with shaders and implementing dyes for every weapon in the game, along with re-coding the inventory GUI will no doubt take a long time.
My fear in this is that the devs won't be able to produce game-changing content fast enough to keep the playerbase healthy and the game fun.
All that said, I have a simple solution to this: I can code up (with a little help from a friend
) this feature, then dm a dev with the source code. They could then test and scan the code, which would implement this feature into the game asap and without anyone batting an eye.