breeding genetics.

Question
My dog's mother was a black lab and father a yellow lab. My dog isn't either black or yellow but a mix of the two. Almost like a rotweiler but not really. The light parts are really light yellow, not tan at all. The body structure is lab too. Do black and yellow labs have bi-color puppies or is it possible one of my dog's ancestor's was not a pure lab but something else?

I love her and don't care if she's not a showdog. I'm just curious how she got this way.

Thanks,

Mary

Answer
Labs and even most Lab mixes are usually almost solid color.  Some pure Labs do have some marking, a white chest blaze, white or chocolate toes, and my one had a white tip on his tale like a beagle.  I have never even seen a Lab mix that was colored like a Rott.  I see hundreds of Labs and Lab mixes every year that are not being bred for appearance.  My Daisy was light, almost white except for several darker yellow splotches.  Her grandmother Spice was allowed to pass on her variegated color to many dogs.

I am hard put to explain her.  It is common for a black/yellow breeding to produce yellow, chocolate, and black puppies, but not bicolored puppies.  How well was the mother protected when in season?  Given a chance, a female will mate with more than one male and produce a litter with different fathers.  My friends have a Lab/Border Collie mix, and Lab coat with BC spots.  One of the few Lab crosses not solid colored.