My daughters black labrador has just had 7 pups, bred from another black labrador. There is 3 chocolate, 1 golden and 3 black. One of the black pups has a very small white patch of fur on its chest, just under its front left leg. My mum says its a throwback...What is a throwback?
It's an animal that has inherited one or more characteristics from further back in its bloodline - maybe grandparents or great-grandparents - usually colouring.
As Andy says, a throwback is usually a person or animal who shows characteristics from a previous generation. In this case, the chocolate and golden pups are really the throwbacks because they got their color from grandparents or earlier.
I hope your mum isn't thinking of throwback as something valueless, like an undersize fish you would throw back into the river. However you may be right that non-conforming coloring could make a show dog or breeding dog less valuable. I have a friend who got a great price on a lovely Samoyed because its nose was pinkish instead of black.