It would be a huge QoL change. I also don't think being able to store dyes in the glamour dresser would tank the market. They would limit the amount you can put in the dresser, and then there is the inconvenience of having to port and take a mount over to one of the beast tribes that sale exclusive dyes, or gathering the pigments for the ones that can be crafted. And rare dyes will always have market value.

Pigments and rare dyes take up quite a bit of inventory space on their own. A change like this would alleviate a lot of inventory management without having to add inventory space. It's basically an ace that the devs simply have to choose to use because modifying the glamour dresser to take dyes along with prisms and glamours would be very easy to implement. I just hope they wouldn't do it in a way where dyes, prisms, and glamours share the space.