A jockey must wear the colors of the owner or owners of the horse he is riding (except by special permission of the stewards, which permission shall be posted on the bulletin Board, together with notice of the colors the jockey shall wear), and the number of the horse is as exhibited after weighing out. When the horse is being warmed up, the same number must be exhibited upon the arm of its rider.
Ill. Admin. Code tit. 11, § 1411.5