Our kittens went for their first jabs yesterday, and their vaccination records include info about bread and colour. I was surprised to see that one was listed as 'black and white' when to my mind he doesn't look black and white at all- I'd have said he was a grey/brown tabby. I queried it with the vet in case they had their kittens confused, but she said technically that's what he is 
But he doesn't look black and white to me! Is there some obscure system of cat colours I've never heard of (like grey horses)? If so, how does it work?