Dapple

n.
  1. One of the spots on a dappled animal.

a.
  1. Marked with spots of different shades of color; spotted; variegated; as, a dapple horse.

The word is used in composition to denote that some color is variegated or marked with spots; as, dapple-bay; dapple-gray.
v. t.

  1. To variegate with spots; to spot.