With Cal kings, it seems that brown tends to dominate, but the babies may appear very black for awhile. This tends to be the case. Remember though, with adults from very mixed genetics, the outcome can vary somewhat.
Case in point (I did many of these pairings with different individuals) I bred a brown and yellow wild Cal king to a black and white Cal. The babies hatched all black and white to my surprise. As time went on, the babies grew and gradually changed to more brown and more of a very pale yellow. As adults, these snakes were brown and a very pretty light yellow. So in that case, both brown and yellow seems to dominate, though it is quite clear a blend is occuring rather than any kind of recessive trait. That is how we know B&W Cals are not anerys. Breeding one of these offspring to a black and white produced pretty much the same results, though on some the yellow was more pale and the brown was darker on some.