One of the issues with the service manual is that there is no guide to what a wire is based on color. All you can do, manual-wise, is to go to each section of the wiring chapter that MIGHT apply and look for the wire color combo.

In this case, that would be:
Front lighting
Turn Signals
Instrument cluster (contains sensor wire colors all over the car)
Horn/Cigar LIghter
Vehicle Speed (probably not but you never know)
Antilock brakes
Body Control Module (that module is involve din EVERYTHING in the car)

There are aspects to the service manual that make it hard to find what you are looking for.