Originally Posted by rryman
...snip... I don't know that there are any hard and fast rules about color coding though.
RV's definitely do NOT have any standards whatsoever!
The lighting may use the 4 wire (brown running lights, yellow left, green right (or is the other way around?)) Generally, white is ground or neutral or negative. Black or red will be 110/220 hot. Unless it's 12V positive. Green or green with a yellow trace should be 110/220 building ground.
Then they don't bother with special colors for the furnace, A/C or other system control wires.
Any repairs ignore color coding as well.