Major League Baseball fans watching a ballgame today can usually differentiate between the away team and the home team due to the color of the teams’ uniforms. Most teams will wear white uniforms (or team-colored jerseys with white pants) when playing at home, whereas when a team is playing on the road, uniforms are typically gray.
Much of this has to do with history. Looking back in baseball history, traveling teams did not have time or access to laundry service to wash their clothes in the late 1800s. As a means to hide the dirt and the mud that would accumulate on the road, teams opted to wear gray uniforms. Over time, with the expansion of the laundromat industry and the ability of teams to bring along multiple uniforms, hiding dirt became less of an issue. It became simply a matter of tradition for teams to wear gray for away games.