The Dun gene is a dilution gene that can lighten any body coat color in varying degrees. The dun must prominently display a dark dorsal stripe and zebra stripes on the shoulders and horizontal stripes on the legs. At least one parent must be a dun.
The Silver gene is a dilution gene that affects only black pigment of the mane and tail and dilutes black body color only slightly. The mane and tail are lightened to a silvery or blonde shade, and the eyes can range from hazel to dark brown. The Silver gene is only expressed on black and must have a parent with the silver gene. Bay Silver horses appear to be chestnuts with flaxen or silver manes but genetically are bay horses. The combination of base coat color and the term "silver" is required to describe a horse with a silver gene such as black silver, bay silver, classic champagne silver, etc.