Silks (or colors) are the colorful jackets worn by a jockey during a race. The origin of the modern jockey silks comes from England.
However, in ancient Rome, chariot drivers may have been the first to sport “racing colors.” They wore capes and headbands in bright colors to identify themselves. Although horse-racing meets are recorded as far back as 1114, individual silk colors are first mentioned in 1515 when Henry VIII occupied the throne. The costume itself was established in the latter part of the 17th and early 18th centuries. As the sport grew confusion resulted from the duplicity of entries which arose. It became absolutely necessary to vary color and design for positive identification. Both judges and spectators began to complain of the confusion. In 1762, the English Jockey Club requested that the owners submit specific colors for jacket and cap and to use them consistently in an attempt to distinguish riders among a field of horses or to settle disputes that might arise.
As racing has changed, so too have colors. Called silks because the early variations were, in fact, silk, today most are actually nylon or lycra. Aerodynamic silks have become more popular in recent years. While in their earliest iterations silks were merely different colors, today the designs can be quite intricate, ranging from geometric patterns to pictures and symbols. Approximately 28,000 sets of silks are registered with The Jockey Club today.