The coat patterns seen in dachshunds are brindle, dapple (merle), piebald and sable. Piebald-patterned dachshunds will never have blue in their eyes, unless the dapple pattern is present. In dachshunds the merle marking is known as "dapple". If a dachshund has one single spot of dapple, it is a dapple. Many breeds do not possess the silver dapple gene. The silver dapple gene in horses does not affect the eyes, skin, or red pigment. The silver or silver dapple gene acts only on black hair. Silver grulla may also refer to a grullo horse with silver dapple, regardless of shade. In spite of its name, the silver dapple gene has nothing to do with graying. It does equally well in sun or dapple shade. "Dapple Rose" features lyrics from Powell on an elderly horse. The silver dapple gene survived for two reasons. Genetic studies have shown that it is closely tied to the silver dapple gene. The tendency to dapple may also be, to some extent, genetic. The B-side, "Dapple Rose", was written by Lea and Powell.