I really like the wide variety of dyes to collect. I want more things to use them on!
In GW1, we could dye our bags. Perhaps, in that same spirit, you could offer us the option to dye other elements of the game besides our clothes and armor.
I think the weapons should be off-limits for dyes, as they really aren’t designed with dying in mind and they already look amazing.
However, perhaps we could have the ability to dye our UI. This could include our bags, our hero window, and so on. Perhaps, in a much more ambitious project, this could also include dying objects in “home” instances. Certain pets might be amenable to custom dye jobs.
I would pay money (gems) for the ability to use more of my dyes on nearly any plausible thing.