Answer:
No, it's not. A Labrador can come in three main colors which are cream, black and chocolate the ones I seen anyway a lot of people in my area have chocolate labs and are such great dogs, the color chocolate is not a defect in this breed at all, its actually a well sort after color and my choice of colors in the Labrador's if you google the breed you will come up with alot of information on the breed including what colors are acceptable in a purebred Labrador Retriever hope this answers your question.