Spawning mobs with an egg on certain blocks gives variants

So in minecraft, if you don’t know how commands work, there’s certain mob variants you have to work for to use, like the frogs, for example. Well I suggest changing it to if you spawn a frog on snow for example, it becomes a green frog, and if you spawn it on sand or a hot biome block, it becomes a yellow frog, or maybe they just have a random chance to be any three, like the axolotls and their variants, and sheep with theirs, it’d be a simple quality of life change to make it a lot easier to obtain variants of mobs for your creative world, with the new dog breeds coming out, it’d be nice to have this, same for villagers, foxes and probably a few others I’m missing.