(Cluster) Speed sender wires

Hey guys,
I have made my custom autometer guage cluster in position of the OE. One problem I am having is my speedometer. I need to know what colour the sender signal wire is and the return wire colour from the ecu to the guage. I usually have access to a shop computer to figure all this out but am out of luck until tuesday. Do any of you guys know what colours I need for signal and return? I would love it if some one here could help me out this weekend. Thanks in advance.