My half-baked idea!
I was thinking, what if we could tint button textures (individually too not both at once), I've got quite a few things that need accent colours other than just images and all that so it would be much easier if I could use one whitish-grey hover texture and just tint that (for some things - not the main buttons because I'm sorting out resource packs for those), yeah I've no clue how possible this is but it would be a nice option to have.