I think it could be a variant of either the hypo or lavender gene, or it could be another gene but allelic with hypo and lavender. I know this guy who owns a pair of rather pinkish Black Ratsnakes. Not a pretty shade of pink (assuming such a shade actually exists...), but a rather drab, liver like shade of pink. He calls them "hypo's", but they produce higly variable litters: lavenders, brownies (true hypo's), and ... grapes. In European collections, grapes actually aren't that uncommon, but often they are labeled wrongfully. For instance, the pair I bought at the Houten reptile show last year, were labeled as 'brindle's', which they obviously are not.