Hope this helps everyone!
On the Flight Deck the crew wear a variety of brightly colored shirts. Here is who they are and what they do:
Yellow Shirts: Flight Deck Officers and Plane Directors.
These are the only people on the flight deck authorized to move aircraft, or to give hand signals regarding taxiing the a/c, or moving it. Blue Shirts: Flight deck crew, always work under the direction of a Yellow Shirt Director as part of a designated crew. Plane pushers/handlers; chock planes, push planes, scrub the decks, and do all the tough jobs on the flight and hangar decks.
Green Shirts: Catapult and Arresting Gear people. Operate, and maintain the Catapults and Arresting Gear. Squadron Aircraft Maintenance people also were green. Brown Shirts: Squadron personnel, in particular Plane Captains. (No ship's company wear brown shirts.)
Red Shirts: Aviation ordnance crews. Load and "arm" those weapons on the aircraft. Sometimes referred to as "BB Stackers", or "Ordies". Purple shirts: Aviation fuels people. Referred to as "Grapes". Gas aircraft. Operate & maintain carrier avgas/jet fuel/ av lube oil systems.
Checker shirts: Squadron maintenance Quality Control people. Responsible for final overall checks of a/c readiness before launch. White shirts: Mail and people handlers for carrier on board delivery (COD).
White shirts with a Red Cross: Medical corpsmen assigned to flight deck during flight quarters. White shirts with a Red Cross are part of the crash crew.