Gem seems to have some other genetics involved, the light shading on the ears is fascinating.
Anyway, the shading gene on the Californian/Himalayan/pointed white color pattern has nothing to do with tort. This is due to how the 'C' color gene works. Full color, like torts or chestnut agouti, is the dominant choice on the 'C' gene. All rabbit colors are due to the pigment
melanin. There are two different pigment factories in rabbits, that color hair/skin/eyes. One does the dark colors like black, blue, chocolate, lilac. The other makes the yellowish fawn/cream/red/orange colors.
Dominant 'C' full color has both pigments working. Not all color patterns need both pigments, for instance, black only needs the dark pigment, but both colors are capable of working. The next option down on the gene is called chinchilla--here the dark color works great, but the yellow shades don't--everything that would have been yellowish turns out pearly white.
Sable is the next option down, not only does the yellow not work, the dark colors are not quite full color--jet black becomes dark sepia brown. Your pointed white is the next option down, no yellows, and no color on the body, just on the points. The last option is the albino red-eyed-white.
So, the fact that your pointed white has points is due to the
c(h) Californian gene. Bradley is a broken black, which is a recessive non-agouti self color. Now we move to the 'E' gene, that decides how the dark color extends down the hairshaft. Black and pointed white are both normal extension. Recessive to that is the harlequin gene, that spreads the agouti bands of color on the hairshaft to different patches of skin instead. And most recessive is the fawn non-extension gene, that puts the yellowish fawn shades down the body hair instead.
On an agouti rabbit (the ones with white eye rings, white inside the ears, and white bellies), the whole rabbit looks some shade of orange. If the bunny doesn't have the agouti gene, but is a self color like black, the body color is still fawn, but the points retain their normal dark color. That we call tortoiseshell--recessive non-agouti, dominant full-color, recessive non-extension
aa C- ee.
This tells you the parents each have a recessive non-extension (fawn) gene to pass along, and each has the recessive non-agouti self gene. The buck is already a self color, so he is already
aa and can't pass along anything else. Pointed whites need to also be self colors for showing, although they can be agouti based.
So, yes, you can definitely have a tort out of this mating, even without knowing there was a pointed tan-colored rabbit in mom's litter. The pointed tan could have simply been a poorly colored tort, or a diluted lilac or blue tort, which has much paler color. The sable gene is also a possibility, which is on the 'C' color gene, not the 'E' extension gene.
