The "lavender" gene (lav) in the chicken causes the dilution of both black (eumelanin) and red/brown (phaeomelanin) pigments, so according to color background, dilution due to "lavender" gives a sort of plumage color patterns: On an extended black background, this condition causes the entire surface of the body an even shade of light slaty blue, which is the typical phenotype known as '"self-blue"'.