Where did your male come from? Two not particularly likely scenarios I can think of:

1. Your male is an ultramel, maybe het caramel also. Maybe some of the babies are ultramels, some caramels, and perhaps some both.
2. Your male is a chimera with some of his reproductive organs from a het or normal sibling. Maybe you also have the hypo gene on one side or the other and the lighter caramels are het hypos. Or for all I know maybe ultamel is like hypo and the hets are often brighter so maybe the light ones are the caramels that got the het ultramel gene from mom.