If they are the same species, they may be able to cross breed, but if there are members of their own species available, this probably won't happen.
It's helpful to know what species they are, exactly. The colours alone are not much help, though from what I've read, solid colour rabbit snails are all from Lake Poso, thus, Poso rabbit snails. They're so similar, it would surprise me if they can't cross, but likely they prefer their own kind.
In the orange Poso, females are larger at maturity than males are, but that is not much help if they are not full grown. So far as I know, the size difference is true for most, if not all of these snails.
Orange Poso snails also have antennae that are distinctly different lengths. A Univeristy prof' friend of a friend who studies in this area thinks that the antennae are a clue to the sex. Long ones and shorter ones.. which is which, I do not know, but I got four, two short antennae, two longer antennae, and they have produced offspring, so I for sure have both sexes.
Yellow Poso rabbits don't have the same antennae.. in fact, they rarely unfold them enough to even tell how long they might be. So they may not be able to cross breed. Yellow ones often are more of dull greenish yellow intend of a real yellow, but are clearly the same species.
Lake Poso is in the Sulawesi area and sometimes the snails are just called Sulawesi snails, but there are dozens of species from this area. Some are quite rare and costly. A lot of them are members of the Tylomania family, but I don't know if they all are.
