Out of the seven purebred Californian kits we got out of our first breeding, one kit has always been a silvery-gray color.
A little research has indicated that eventually this gray will recede to white and this kit will probably have the best color points out of all of them.
Like in Siamese cats, the dark color points on the extremities of Californian rabbits are due to a form of albinism, resulting from a mutation in tyrosinase, an enzyme involved in melanin production. The mutated enzyme is heat sensitive and fails to work at normal body temperatures but becomes active in the cooler regions of the skin. This results in dark coloration in the cooler parts of the body.
This means if your Cal has some strange dark spots or coloration where it shouldn’t normally be, it’s probably because of cold spots in the environment. Never fear though, with their next molt your rabbit should be back to its original, glorious white.