High Quality Content by WIKIPEDIA articles! The official rules of Major League Baseball require that all players on a team wear matching uniforms, although this rule was not in force in the early days. Originally, teams were primarily distinguished by the colors of their stockings and the success of the Cincinnati Red Stockings popularized the adoption of sock color as the explicit identity of the club. The 1876 Chicago White Stockings actually wore caps of different colors. In 1882, the National League assigned stocking colors to the member clubs: red for Boston, white for Chicago, grey for Buffalo, blue for Worcester, gold for Detroit, green for Troy, and so on. That year, the league also assigned jersey and cap colors, but by player position rather than by club.