I'm looking for a chocolate lab puppy to replace my black lab who passed in November. I've been talking to a guy who has some pups, he has sent me the pedigree for the parents and discussed all the health clearances. He currently has two females from the same litter. One is completely brown the other has some white markings on her chest. I've read on some other forums that the dog can still be a purebred, but the white marking is not desirable. I always heard that pure labs do not have other markings/coloring. What are your thoughts. Thanks.