[CoL] Cannot Make Rainbow Animal Treat with Rainbow Egg

I'm adding to this thread, however it may be a different problem. Not sure. (I was playing with my Test Save for CoL, so the eggs have been waiting in the fridge for a long time.) The description for Rainbow Eggs says they can be used for Rainbow Treats, however the game won't allow me to make Rainbow Treats with anything but Green, Blue plus Orange Eggs.

Tried Repair Game and Reset the save. Currently no Mods, but I may have tested some in this Save back when CoL came out.