My first black rhino! The black rhino is actually not black in color, but brown or grey like its cousin the white rhino. One of the main differences between the black and the white rhino is the shape of its lips. The mouth of the black rhino has a slight V-shape, unlike the white rhino which has a straight mouth. This is why the species are also known as hook-lipped rhinoceros for the black, and square-lipped rhinoceros for the white.