All armor glitches on the horses from this mod. Except for the three vanilla sets and the netherite one added by this mod.

Modded armor made for the vanilla horse model does not fit this one. No surprise there, and unfortunately I won't have time to go and make compatible versions for every horse armor mod. Any modders interested in compatibility are encouraged to extend https://github.com/sekelsta/horse-colors/blob/master/src/main/java/horse_colors/item/CompatibleHorseArmor.java