offspring of labs

Question
Can a yellow lab birth chocolate or black labs in a litter as well as yellow labs. If the mother mated with another dog (not a lab) could she still have pure lab offspring or will the pups always be a mix. Thanks.

Answer
Yes it is quite possible if mated to a black depending on the genes the black carried.  Some blacks will only produce blacks. Some blacks will not produce chocolates.  

Any puppy will be half whatever its father was.  It is possible for some of the puppies in a litter to have different fathers if the mother mated with more than one male.  .