Pastel Calico is one of my favorites..
As far as cross breeding I would learn all you can about your first ball python that you can, there is cross breeds but breeding a ball python to a ball python can be trick all in its self with out messing with major genetics platforms of cross breeding.

Not to mention the negative mutations Ive seen from cross breeding so take it one step at a time..

Trust me your first lesson will be that breeding isnt as easy as people think it is.... But good luck on your venture....

One more piece of advice "Take good care of your animals and they will take very good care of you when it comes to breeding and keeping them healthy"...

Greg Jeffery