Presently we know the Lab as being Black, Chocolate & Yellow as registerable colors with the AKC, although originally, they were bred to be just black in color. The first yellow came into existance in 1899, chocolates folowed in the 1930's . Both were met with reluctance & not immediately accepted into the AKC breed standard. Now Silvers & Charcoals are following in the footsteps of the pioneering Yellow and Chocolate ancestors.
At this time, because of the variations set forth in the breed standard of colors, Silvers will be registered as Chocolate and Charcoals as Black. Up until 1987, those that listed "silver" as the color of their Lab were able to register them as such with the AKC. The AKC currently recognizes the silver color as a shade of chocolate that ranges from sage to dark chocolate.
Read the full article: The Great Dilute Debate