All the sets I would want to dye have already been recommended, but three things I want to say-
One: Please quit making sets where the cloth and the metal both dye. It makes it so that some sets look garbage if they are dyed any color that's not a natural metal tone, most of which are boring neutral colors which look boring on the cloth portion(grayscale and light yellows/browns). The choice therefore becomes gaudy un-metal metal, or drab cloth segments with real looking metal. I know this can't be fixed in-full without multiple dye channels, but the simple solution is to just make the metal not dye (in a lot of sets this is already the case, more of that!)
Two: Please stop making it so that when gear is dyed it has a sudden drastic texture change. If it looks like smooth cloth but turns to a shiny leather-texture when dyed it becomes way harder to match to outfits. Same is true with some metallic armour being "painted" matte colors instead of retaining its finish. Keep the texture/finish consistent please, nothing sucks more in the glamour game than thinking you found the perfect boots or gloves only for them to become shiny when dyed.
Three: All the desaturated ugly gray-ish color that happens to things like undershirts, leather adornments and sashes almost never looks good. Leave things like that the original color or have them dye the same color as other bits. In general changing only some of the colors on gear with lots of white/black/brown would look nicer in most cases than the weird multi-tone cover-all job. Some gear has this idea down already, like the Scholasticate coat or the astrum silk robe, but other times not so much. If I dye something wine red I want all or part of it to be wine red, not two to four different shades of red one of which is wine red while the others don't match anything.
EDIT: I LIED- MAKE BOGATYR'S CASTING/HEALING SET DYEABLE PLEASE