The Corsair has two little windows on the leading edge of its wings. One contains the gun camera while the equipment in the other helps the plane land on an aircraft carrier at night.
The “Approach Light” is a regular-type light bulb situated behind a multi-colored filter. The filter has horizontal bands—top to bottom it’s green, a thinner line of amber, and then red.
The pilot can’t see light as the plane lines up for landing on the carrier deck, but it is very visible to the LSO (Landing Signal Officer) below. The light gives the LSO information on the attitude of the plane, even when it’s a pitch black night.
If the plane is nose-high, he sees red. It means the Corsair is approaching too slow. If the plane is nose-down, coming in fast, he sees green. If the plane is “right on the money” to intersect with the deck right in front of the arresting wires, the LSO sees a soothing, satisfying amber shimmering from the left wing of the fighter.
It should be noted that in modern carrier jets, the order of the colors is often backwards from the 1940s version—red equals fast and green equals slow.