Very subtle differences. Google them and look at as many pictures as possible. A good way to see how they combo is to look at the pastel versions of each.
Go here: http://www.worldofballpythons.com/wizard/
Look up pastel x calico and pastel x sugar
Look at how they vary, and look at what traits are more consistent between the 2, and make up your mind for yourself. My vote is that they're different. Others will disagree. Sorry I can't give you a straight answer.