Supers are normally quite a bit cleaner, with less black in them. Supers can, however, look quite a bit like normals... these are usually questionable as to whether or not they are really supers and are labeled as possibles (they will not be from a super to super breeding, but from normal hypo to normal hypo).
Supers are homozygous for the hypo gene. When bred to a normal, they will produce all supers.