4 conductors? If so, I believe they're wired the same as standard RJ-11 telephone cord.
Looking at the bottom of the plug (looking at the brass contacts), left to right: black, red, green, yellow.
It's probably only using the two center wires though which would be the red and green.
They may be reversed for some reason though, some vendors do that, I don't know why.
Search the web for RJ-11 pinouts.