Wiring Diagram question for '82 XJ750 R(obert) J(ordan) Seca

Hi All,
I am putting my wiring harness back on my bike and in the head lamp area I ran into a jumble of wires that mostly coupled back together with mated plugs but some single wires were left unmatched. Since I am new to this I decided to do something simple, trace out the rear brake switch circuit. The Haynes wiring diagram states that from the rear brake switch itself to the head lamp junction it is a solid yellow wire all the way. I disconnected the wire prior to testing. When I probed for actual wire using a continuity tester it starts out as yellow and ends up GREEN! What am I missing here? Is the Haynes wiring diagram in error? Am I accidentally testing other circuits? I have studied the five fused mini-circuits (main, head, signal, ignition and the one hidden in the head lamp area) in the manual and some connections don’t make sense and some wires cannot be found on the actual bike. Any suggestions? One additional note, I have not connected any grounds yet.

Thank you guys for all your help,
Kent

 

Nevermind. Rookie mistake. I missed a small part of the wiring diagram in the lower left hand corner detailing the y/g wires for the Check and Warning Control buttons. The wiring in the head lamp area is complete and secured out of the way of the head lamp with the clamps from the internal horns and the head lamp is installed. On to the rest of the wiring...
I did learn another thing, there must be joins of different colored wires in the wiring harness, I thought these joins were made only at the points where the different components connected. It must have made more sense to connect these wires at the most design-effective points in the wiring harness.

Thanks for not flaming me,
Kent