I don't know of any hets that cause a red hue. Caramel tends to give a yellow wash, bloodred tends to alter the belly checkers, sunkissed alters the pattern and supplies a pissy attitude, and it seems to me like the motley and stripe genes tend to give the snake a precise pattern... All in het form. Those are the only "het markers" I know of, though, and I'm not sure there are any more (except maybe one more for bloodred).