Buckskin is one copy of the cream dilution (CR) on bay or brown. The cream dilution mutation is found on the MATP gene. Cream is an incomplete dominant, meaning it cannot skip generations and one copy of cream looks different than two copies. Cream lightens the body on buckskins, but not the points leaving them with black legs and black manes and tails. Buckskins can have white streaks or frosting in their manes and tails. Buckskins have dark skin and dark eyes. Buckskins can fade in the sun, and so that their points are not completely black. Buckskin foals legs are not black until they shed the foal coat. There is a test for the cream dilution.
Wild buckskin is one copy of the cream dilution on wild bay. The legs of wild buckskins are noticeably shorter or are barely present. There is not a test available for wild bay/buckskin.
Buckskin and dun are sometimes used interchangeably or mistaken for one another; this is incorrect as they are two different dilutions. A buckskin with a dorsal stripe or other primitive markings does not necessarily mean that it is a dun as countershading can also cause primitive markings.
It is not known when the cream dilution was first introduced into Chincoteagues. The palomino Misty was foaled in 1946 so it would have been at some point prior to that year. It may have existed early in the breed as there are a few accounts describing ponies as dun. Dun is traditionally used to describe buckskins and the term is still used today in parts of Europe. A 1891 article in the New York City newspaper The Sun stated that the ponies "are most frequently black, gray, sorrel, or dun." Additionally the 1910 Pittsburgh Times stated that "White and dun-colored ponies are exceedingly rare." A 1923 St. Petersburg Times article described the ponies as "bay, gray, dun, black, and sorrel". Conversely Leonard D. Sale wrote in 1896 in The Horse Review of Chicago that, "I have never yet seen a grey, piebald, dun, or yellow purely bred island pony."