Noone has really done any chemical testing on the genes of Ball Pythons to find out exactly what is going on with pimentation. However, based on the looks of morphs, and having a good understanding of their true coloration, one can deduce what is going on based on science done on other species. With all of that said, if the theories about Balls are correct, then theoretically it should be a predominantly white snake (maybe some very light shading, or light purples and gresy in some forms). Lastly, I wanted to make a correction to the above statement. Leucistic animals do not lack pigment. In fact all of the pigment is present, however, the chromataphores, cells in the skin that hold pigment either are not present, or are turned off. Therefore, the skin is white. Leucistics, however, do have colored eyes, due to the pigment being present. That is, once again, based on the theory that Lucy balls are actually Leucistic by definition.
I hope I didn't confuse anyone too much,