The only yellow puppy in a litter of black Wavy - Coated retrievers was whelped in 1864. (grca.org)
The appearance of yellow puppies in this litter illustrates two principles of genetics — you can't always tell what the pups will look like by looking at the parents, and the pairing of genes is akin to a roll of the dice: it's almost impossible to predict which combinations will crop up. (canismajor.com)
If both parents are yellow labs, regardless of what the B alleles are, you will always get yellow puppies. (easyretrievertraining.com)