I had a tire blow out on my trailer and it took out my wiring and trailer light. This is wired more complicated than any diagrams I can find.

On the Right side of trailer, (boat driver side-truck passenger side), there is a wire that is white with a green stripe. What is this wire for?

Basically, I have 3 wires from the front, (Brown, Green and this white-green striped wire), and my new light has two wires Green and Brown.

Any help appreciated, thanks.