When correctly wiring a boat's electrical system, remember that the red wires are used in the positive mains and the black or yellow wires go to the negative mains. Run the green wire to the bonding system and the light blue wire from the oil pressure sender to the gauge.
The dark blue wire is used for cabin and instrument lights and runs from the fuse or switch to the lights. The gray wire runs the navigation lights and tachometer, and the orange wire powers the accessory feed. Pink is the color for the fuel gauge, and tan controls the water temperature gauge. Run the yellow wire with a red stripe from the starting switch to the solenoid and the brown wire from the generator to the alternator. The brown wire with the yellow stripe powers the bilge blowers and the purple wire powers the ignition.