Well, I certainly can't say which is correct, because I never even heard the term until I got on this board, but of my two black and whites, I consider only Big to be a "tuxedo" because he is the only one who looks like he's wearing a tux, although it's hard to tell in the only digital pic I have of him:


Cookie, on the other hand, would seem to me to just be a patched black and white, since she does not look like she has on the coat and white blouse-again, it's a little hard to see in this picture:


If you could see Cookie's back end or see her straight on from the front you could see better what I mean - all her patches.

It certainly seems to me that only B&W cats could be called tuxes, since that's the traditional color and the purist's choice.

But this is just my impression, I really don't know the cat fancy standard!