Also noting that you can occassionally get a "tortiose shell" esque male cat via a pretty rare process known as chimerism. i.e. two or more different embryos merge in the womb resulting in different parts of the body being formed from different embryos (meaning different DNA depending what part of the body you sample from). And of course for this to result in a cat you can see, they have to get lucky enough that the combination of embryos still produces a viable fetus.