Only white horses spawn

Hello. I recently noticed that I can only spawn white horses. This is starting to get annoying as i want more variations. I’m on IOS and have tried removing and adding texture packs. I even made a copy of the world but i can still only spawn white horses. Does anybody know how to fix this? And before anyone asks no, this problem is just for one specific world. However this is a world very dear to me that i don’t want to lose? what should i do? Please help!