Likely RS-485 color coding of three wires?
Joe - forget about hopes of finding a standard color scheme. 

The simplest thing is that the Reference (Common) lead will connect to the GND of the circuit. That should be dead simple to discover which one with a multi-meter. 

Finding that the other two will be the A and B lines. Hook those up one way and see if any protocol makes sense. If not then hook them up the other way.