In the popular television program 'Star Trek' the Federation members on the U.S.S. Enterprise wear different colored uniforms based on their job on the ship. Officers wear red. Engineers wear yellow. Medical staff and scientists wear blue.
Common characters such as Spock and Bones are associated with their iconic blue uniforms, while Scotty is associated with his iconic yellow uniform. However, the show also makes frequent use of extras in myriad colors. These Federation members frequently wear red to signify they are of a low rank - often Ensign.
A trope on the show is for the crew to be beamed down to the surface of a planet. Often the situation is dangerous and a task force of five or more members is required. Typically the crew will include four recurring characters and one 'redshirt' - a nameless faceless extra. It is very common that this character would die immediately upon transport, alerting the rest of the team to imminent danger.
In the NCAA XC Championships, you are only allowed 7 runners. It is very common to clothe the rest of your members in red for good luck in keeping with the trope. This way, if anyone is to die, the stronger members of the team will be alerted and will be able to run away faster than their slower teammates.