I don't want green dye to do anything new. I just want the ability to craft it.
I don't know of this "green wool + green wool = green wool" recipie of which you speek, but "green dye + bone meal = lime dye" is also useless without acess to green dye.
You had originally said: Fix for that useless "white wool + bone meal = white wool" recipe.
Technically, the recipe is ANY COLOR WOOL + Bone Meal = White Wool... just like the recipe for Green Wool is ANY COLOR WOOL + Green Dye = Green Wool.
You stated that the first recipe was useless... which it isn't when applied in the correct context, which would be to change the color of non-white wool to white, just like the green wool recipe is best if used to change non-green wool to green. but they are both useless if you are using the same dye color as the starting color of the wool block.