Welcome to the Side Imaging Forums JDGuess. 
Are you asking about the wire color for the GPS Receiver ‘pigtail’ wires? 
If so, which set do you have: Red, White and Black or Green, White and Black? 
On both sets, the Black is NMEA Ground and White is the NMEA + or output but so is the Green wire connection (it uses a different prefix on the NMEA sentences though). 
Give us some details on what you have and what you are trying to connect to.