Blue is a solid color which is actually light to dark grey and often has a bluish cast. The undercoat is also grey. Blue puppies are born the color of silver or appear black before developing a silvery grey undercoat and a darker slate blue top coat.
Some Blues may be so dark that they appear Black until they are seen next to a true representative of those colors. The points (eye rims, nose, lips and pads) are blue. If the coat contains any other color, the dog is more properly referred to as a parti-color, or bi-color.