People use the term IMG to describe the pigment loss in some ball pythons. Don't ask me why but they do. It is actually a wrong term, as IMG is increasing melanin while this strange occurrence is losing melanin. This snake does look like it could be a pastel that has lost its color. So far, to my knowledge, all ball pythons that have done this do eventually get their color back after a few years. No one knows why this happens, but it is speculated that it could be some type of nutritional deficiency or stress. It does not seem to be genetic.