Give resource packs full control over all colours?

There are plenty of examples of textures that just cannot be changed because of any number of reasons, but mainly that certain parts of textures are hard-coded to be a specific way. We have a colourmap for grass and foliage, and I think it's about time we get an equivalent for redstone, water, collar colours, sheep colours and anything else that doesn't currently have a way to be changed. (It's weird when you want to make the water red and it comes out as a weird green colour.)