and at least one dun allele. These are quite difficult to tell apart from ordinary duns. They are a slightly paler shade, and retain their dark points and primitive markings. Cream dun, cremello dun or linebacked cremello: a blue-eyed cream horse also carrying the dun gene. The primitive markings associated with the dun color are usually quite visible, especially on horses with a bay or black base coat. Smoky grulla, silver grulla or smoky black dun: a black-based coat with one cream allele and at least one dun allele. The effect is of an extra-pale grulla. Double-cream champagne: any blue-eyed cream horse that also carries the champagne gene. The champagne traits are, in the few known individuals, not visible. The skin is quite pink. Amber cream or buckskin champagne: a bay-based coat with one cream allele and at least one champagne allele. The skin and eyes have champagne traits such as skin mottling, while the coat is a pale buff color. The points are a soft, pale grayish-chocolate. Classic cream or smoky black champagne: a black-based coat with one cream allele and at least one champagne allele. is also an acceptable term. Like an amber cream, they retain champagne traits in the skin and eyes, and range from pale buff to pale chocolatey-gray. Even though the coat is black-based, the mane and tail tend to be darker. Gold cream: chestnut-based coat with one cream allele and at least one champagne allele. Formerly referred to as "ivory champagne." The champagne traits remain in the skin and eyes, and the coat is an all-over ivory color. Sable cream or brown buckskin champagne: brown-based coat with one cream allele and at least one champagne allele. The coat color falls between amber and classic cream. Silver buckskin: bay-based coat with one cream allele and at least one silver dapple allele. The effect varies, as silver dapple does not act on red coats, but the buckskin's golden tone is somewhat lost. Silver smoky black: black-based coat with one cream allele and at least one silver allele. The effect varies from chestnut-like to silver black-like. Lighter eyes can help with identification. Inheritance and expression The cream locus is on exon 2 of the SLC45A2 gene; a single nucleotide polymorphism results in an aspartic acid-to-asparagine substitution (N153D). The DNA test offered by various laboratories detects this mutation. The SLC45A2 gene encodes a protein illustrated to have roles