Star Trek: The Red Shirt
The writers of Star Trek were faced with a problem. They wanted to add drama and pathos to their show by having the crew visit dangerous planets with hostile aliens, but they couldn't exactly kill off a member of their main cast every week. The solution? Include some nameless extra who beams down to a planet's surface along with the regular crew, then gets killed off before the next commercial break.
Thus was born the curse of the Red Shirt.
As a command officer, Kirk wears a gold uniform. Science and medical officers (such as Spock and Bones, respectively) wear blue. These three are the most common main characters to beam down to the surface of a planet. All that's left are engineering and security personnel, who wear red. I guess it makes sense to have a security officer beam down to the surface with you, but they do seem to have an awfully high mortality rate. (As the chief engineer, Scotty also wears red, but manages to dodge the curse by being back on the ship and by being a main character.)
This is, I think, all the background you need to enjoy this very funny video: