Trailer wiring???

[JonBoy]

OK I have a 98 Chevy and it came with the wire run to add a electrical trailer connection just without the connector. I am adding one but I have a extra wire. There is 2 green wires one light and one dark. Any clue? Other than that there is a white, brown, and yellow.

 

[dvandiver]

There may be an extra one for trailer brakes but I think that one would be blue.

 

[JonBoy]

Figured it out its the dark green the light green is for backup lights. (I think have not tested it yet).