Seadoo challenger Gauge wiring and aftermarket

[Hawk111]

I am looking at replacing these tired gauges with something more modern and cooler as well. Can someone please help me understand the speedo and RPM gauge wiring? What the colors mean and what each wire is doing. I’d like to replace with these cool glow shift gauges. Here is a picture of my speedometer wiring and a picture of the aftermarket wiring.