Like already said, you need to know what created the bel. There are quite a few possibilities, off the top of my head, Mojave, lesser/butter and bamboo. If you breed one with a banana, you could get Mojave banana ect...

I suggest you go to world of ball pythons and use the genetic wizard if you want your exact combos and odds but you'll still need to know what created the bell or your going to need to breed it to find out which genes it carries.