Everything should be dye-able! honestly IF possible with option to choose 2 different dye's to combine and have a main color and a sub-color so it is not fully red or green or w/e.
for example the house maid shoe's, main color would be the shoe and sub color the socks, on a body piece like thavnarian dress the main color the cloth yet the metal be the sub color u'd be able to dye, and so one for many many pieces! i know this would be ALOT of work for the people who make the game BUT it be soooo worth it!!.