Spider and pastel seem to have the most dramatic effect on the calico gene. My most anticipated pairing is going to be my calico pastel to my bumble bee, which creates beautiful combinations all around (calibees, calico killer bees, caliders, calico pastels, and calico super pastels to name the calico combos). I also like the look of calico enchis, calico lessers, cinnacals, and any combination involving fire and calico. I can't find many pictures of calico axanthics, but that combo also interests me just for the possibility of pure black and white snakes with no grey (no more shades of grey, I'm sick of shades of grey).