Labrador Retrievers come in three colors—black, yellow, and chocolate. Differences in behavior and personalities between the colors have been noted by many Lab owners, though these differences are no more than hearsay. While anecdotal evidence suggests the genes may be responsible for differences in temperament as well as coloring, this phenomenon has not been studied extensively.
A litter of Lab puppies may come in any combination of colors, depending on the dominant and recessive color genes the parents carry. This means a black Lab can produce a litter of chocolate or yellow Lab puppies, if the right genes are passed. Likewise, offspring from a yellow or chocolate Lab can present alternate coloring.
The introduction of a 'dilute' gene at some unknown point in history has resulted in silver-toned chocolate Labs and dilute-colored black and yellow Labs. These colors are not officially recognized by the AKC, and controversy surrounds these unique colorings. Some believe Weimaraner genetics may exist in the bloodlines of a silver, grey, or otherwise dilute Lab, though this idea has not been substantiated.
No. While both were bred as working dogs and share many qualities, they are two separate breeds with distinct characteristics.