This post has been updated with additional photographs here.

The champagne allele, at the champagne locus, was for many years ignored or confused with palomino, buckskin or dun. In fact the first edition of Sponenberg, published in 1983, has some of the same photographs of hoses, identified as “pink-skinned palomino,” or “lilac dun.” used in the second edition (1996) to illustrate the champagne group of colors. It was a relatively rare allele until recently, but is now known to occur in a number of breeds of horses, and is becoming more common due to selection for the champagne colors.

The champagne locus has two alleles, champagne and wild-type. Champagne is dominant to wild-type, though a horse with two champagne alleles may be slightly lighter than a horse with one champagne and one wild-type. In general, however, one cannot look at a horse in the champagne color group and say whether one or two copies of champagne allele are present. Certainly the difference is not nearly as marked as between buckskin and perlino.

The diluting effect on red is similar to a single cream allele, but champagne has far more effect on black pigment than does cream. Since the pigment in the skin and eyes of all horses is black (eumelanin,) eyes and skin color are affected by the champagne gene. Skin color is paler than normal, often with some mottling. Most champagne foals are born with blue eyes which darken to amber, and the foal coat is often darker than the adult coat.

Champagne also tends to produce a very shiny look to the body coat. In the case of champagne imposed on clear chestnut, the result is an almost metallic gold color. These gold champagnes are easily confused with palominos, and in fact may be closer to the “new-minted gold coin” body color than the commoner dark-skinned palominos. Genetically, however, they are quite different, though both are dilutions of chestnut base color.

If the base color is black, the result is what is called a classic champagne. The color is not uniform. The body is diluted to a sort of pinkish beige, but the mane, tail and to some extent the lower legs are a darker shade of brown.  Why this contrast occurs when the base color is uniform black is not clear—microscopic examination of the pigment granules is needed in champagnes, as in another color group, the silvers.

Champagne imposed on bay gives amber champagne. Horses of this color have a shiny yellow to tan body color with chocolate points.

Both bay and chestnut vary a great deal in the depth of red color and the amount of interspersed black hair in the body coat, and the addition of the champagne gene does not change this. Thus there is a wide variation in the exact shade of color in the various types of champagne.

I’m sorry I couldn’t get photos of champagne horses to go with this bog, but there is a facebook group with a number of photographs.