I was under the impression that torties are the brown/black/orange pattern, and calicos are that but with white, but maybe a cat expert will come enlighten us
or I could just google it
supposedly calicos are white-based with large patches of black, brown, and orange and the colors don't usually mix, while torties are brindled/mixed together and mostly darker. torties can have white, but white-based cats are calico
that's probably very non-scientific and simplified, but ~yay~
Torties and calicoes are the same, but are classified as either one or the other depending on the white spotting percentage – 30% and less is tortie, 31%+ is calico.
Torties are always ginger mixed with black, brown, or another nondilute color (like cinnamon), but dilute ones are always cream (dilute ginger) with blue (gray), light brown, or another dilute color (like… fawn? I think?). Brown/black, blue/ginger, and black/ginger, for a few examples, aren't genetically sound O:
Torties always have XX genes because X carries one pelt color apiece – meaning if you want to mottle two together you'd need two of those bad boys. There are XXY cats that are designated male at birth, but those are usually sickly and infertile (and often don't live very long if not cared for!).
Redtail and Sol are both assumed XXY (and fertile, given Redtail had kits?), but I really like trans Redtail (and probably trans Sol), myself!
Cue cat expert. ^^
That explains a lot and actually might help with future OCs…
Apparently Redtail is fertile, but the Erins have said before that they don't actually know much about genetics or anything of the sort, hence why we have tortie toms (which is supposed to be damn near impossible to even get) who last much longer than kithood. We have Redtail, Sol, and Robinwing of RiverClan that I can remember. I don't know if there are any others- we have such a large cast list, so I wouldn't be shocked if I forgot one…
Not so much a cat expert, but after tryin' to make realistic cat characters I had to do some research myself! o/
I didn't know about Robinwing, hmm. I still prefer my trans headcanons to making 'em infertile and sickly – I just wish the Erins had done some actual research.
Speaking of: Kate actually posted about that particular topic. The site is a bit slow to load (book spoilers within!), but one of the last questions she's asked pertains to how much research they did.
Welp! Okay. Making a cat book in a realistic setting? Just throw all cat genetics and related subjects out the dang window. That's the Erin Hunter Way ™!