There seem to be SO many hypo lines out there. I myself own a "green" ghost male, beautiful, awesome, killer animal. But what can he breed to to produce more hypos???? I have no clue. He looks a lot like a lot of yellows, but the only way to know what he can do for sure is to breed him to other ghost/het animals.
The hypo genes are just too unknown at this point IMHO. There are some proven compatible lines, mostly orange. (See NERD, Bell ghosts, etc.) There are new import hypos coming in every year as well.
The fact is, we don't yet know what lines cross with what. Hypos are a favorite of mine, and overlooked IMHO. There are a lot of morphs to be made and questions to be answered. I know I'm working on 'em. 