Here is the factory wiring colors that were in my 73 duster.
I cut the factory plug and used a Ron Francis connector.
I also used Ron Francis LED's for turn signals, high beam and brake lights.
Fuel - Dark Blue
Dash lights - Orange
12V key on - Blue / White tracer
Turn signal LH - Lt Green
Turn signal RH - Tan
High beam - Red 18g
Brake - Blue/White tracer+ / Black 20g -
Purple - Water temp
Grey - Oil light