That’s right! They’re coded by their jobs! Red vests are for people in charge of ordnance (ammunition and torpedoes), Yellow is for aircraft directors and catapult officers, Green for catapult and arresting gear crews and maintenance, Blue for aircraft handlers, Purple for aviation fuel handlers, Brown for plane captains, and White for quality assurance and safety. The person who oversees Flight Deck operations, the Air Boss, works at the top of the Island superstructure, so he has to be able to look down and, in a glance, see that everyone is where they're supposed to be!