The correct colors of the Cane Corso
Corsos appear in two basic coat colors: black and fawn. This is further modified by genetic pigment dilution to create blue (from black) and formentino (from fawn) colors. Brindling of varying intensity is common on both basic coat colors as well, creating tigrato (full brindle), black brindle, and blue brindle. Fawn also has a number of different expressions, ranging from the pale of a formentino to 'red' to the more common beige color, with the back coat hairs tipped with black. In blue dogs, the nose can appear gray but should be darker than the coat. In all other dogs, the nose should be black. White markings on the chest, toes and on the chin and nose are seen as well, with smaller white patches being preferable.
See correct colors in the photo. Sometimes, incorrect colors are being advertised and sold as "rare" colors, a merit of a higher price. But, these colors are undesirable and considered a disqualification in the breed.
Incorrect colors of the Cane Corso
Colors such as liver or chocolate, Isabella or tawny, straw or wheaten or any color that is not described above, are considered INCORRECT for the breed. Also included are color patterns of black and tan that resemble the Rototiller and the Doberman patterns. These color patterns are considered a DISQUALIFICATION according to the AKC standard.
Some breeders will try to sell puppies/ dogs with these colors as "rare" color, and even will charge a higher price for them. But, these colors are wrong for the breed.