Overrides for GUI

We already have overrides for items in Minecraft like "custommodeldata" or "damage". What about having overrides for GUI's? We can make custom heart colours based on the potion effects we have. Or we can add damaged anvil GUI's. It would be so cool to be able to use these GUI's in texture packs. I suggest adding overrides for GUI's and a few more override values such as active potion effects, how many hearts left, being on fire, being frozen, block is being broken for GUI overrides.