Do the different colors of hookup wire used on Fender pickups and harnesses mean anything?
The different colored hookup wire used on Fender pickups usually designates whether the pickup is used for a specific position to help the assembler put the wires to the proper contacts on the switch. If you had a bunch of wires with the same colors coming through the cavity, it would be confusing what wire goes to what contact for proper pickup phasing and performance. Fender has used several different colors for their hookup assemblies such as black, natural, yellow, blue and green. Wiring a Fender Jaguar or Jazzmaster can be a nightmare without the proper color coding of hookup wires. Also, the different colors can be cut to the desired length to eliminate much scrap or excessively long hookup wires that would have to be cut or wasted.