A black Lab is a Labrador Retriever in the breed's original color, not a separate breed. Labs descend from Newfoundland's St. John's water dogs and were refined in Britain as gun dogs, which explains the otter tail, broad head and dense, water-resistant double coat. Some have a small white spot on the chest, and many gray around the muzzle as they age.
Color doesn't change personality. Black Labs tend to be friendly, food-motivated and eager to please, though field-bred dogs are often leaner and more driven than show-bred ones. Expect a dog that needs daily exercise, steady training and measured portions, and that sheds enough that regular brushing helps keep valley dust and hair under control. Adolescence can be bouncy, and Labs mature slowly.