Icelandic horses weigh between and stand an average of high, which is often considered pony size, but breeders and breed registries always refer to Icelandics as horses. The official breeding goal gives room for substantial variation in size. Several theories have been put forward as to why Icelandics are always called horses, among them the breed's spirited temperament and large personality. Another theory suggests that the breed's weight, bone structure and weight-carrying abilities mean it can be classified as a horse, rather than a pony. The breed comes in many coat colors, including chestnut, dun, bay, black, gray, palomino, pinto and roan. There are over 100 names for various colors and color patterns in the Icelandic language. They have well-proportioned heads, with straight profiles and wide foreheads. The neck is short, muscular, and broad at the base; the withers broad and low; the chest deep; the shoulders muscular and slightly sloping; the back long; the croup broad, muscular, short and slightly sloping. The legs are strong and short, with relatively long cannon bones and short pasterns. The mane and tail are full, with coarse hair, and the tail is set low. The breed is known to be hardy and an easy keeper. The breed has a double coat developed for extra insulation in cold temperatures.