After looking over today's (3/19) COTD, this may sound elementary, but can all blue cats be classified as a Russian Blue, or are some of them of different breeds, that is a breed (or mix) with different coat colors, such as a tortie or tabby?

I have one totally blue cat (and a new kitten which is a long-hair silver-blue), and I also know that she (Bluzette) is part Abyssinian. I am assuming that a Russian Blue is a separate breed of cat.

......wayne