Temperature Gauge Wiring

Hi all, i am trying to figure out the wiring on the back of a white faced temp guage (sorry no pic), mainly what wire goes to the temp gauge sender unit. The wires are: Black = earth, Blue & Red = power to instrument bulb !, Green & Brown ? and Brown & Black ?. The only colour that matches the various wiring diagrams is the Black, i cannot find anything that matches. Help.
Regards,
Tony.