The chocolate Labrador emerged in the late 1800s, with liver colored pups documented at the Buccleuch kennels in 1892. The first dog to appear on the cover of Life Magazine was a black Labrador Retriever called 'Blind of Arden' in the December, 12th, 1938 issue. Labrador colouration is controlled by multiple genes. The first dog to appear on the cover of Life Magazine was a black Labrador Retriever called 'Blind of Arden' in the December, 12th, 1938 issue. Labrador colouration is controlled by multiple genes. It is possible for recessive genes to re-emerge in later generations. Also, there can sometimes be unexpected pigmentation effects to different parts of the body. Pigmentation effects appear in regard to yellow Labradors, and sometimes chocolate, and hence the majority of this section covers pigmentation within the yellow Labrador.