In terms of simple color genes a new zealand red is A_ B_ C_ D_ ee with a lot of rufus and the recessive at wideband to color the belly red. A red belly is desired.
Any tort of any breed is aa B_C_ D_ ee. Cinnamon rabbits are tort and have a lot of rufus as well.
Most breeders who tell you they are giving you a mixed breed, truly are giving you a mixed breed. There simply is no reward in claiming a rabbit is a mutt if it isn't.
Sometimes sneaky people will claim a rabbit is purebred because of it's looks, when it really isn't. That's why pedigrees are so important when it comes to breeding show stock.
Genetically, a meat mutt with the exact same tort coloring as a cinnamon would very likely also be carrying a lot of undesirable recessive genes that would be detrimental to the cinnamon breed's gene pool.