I am not 100% positive what they did back in 1985, however green is the standard wire color for the hot wire (+12VDC) on the clearance lights. And Sunline did use white wire on the year 2000 campers for DC ground (-12VDC)
Does your main battery cables have a white for DC ground? They would of kept the same method throughout the camper.
If you pull the right side (the door side) rear stop light lens off, you should see white as the bulb outside casing of the bulb holder for ground. Green and Brown would be on the center stem of the bulb socket. Again in the year 200 models at least.
Hope this helps
John