Need help with a wiring harness.

[CivilEGR]

Last time I really ran my truck a good amount, I had smoke coming from my wiring harness. It's all original and cracking really badly. I'd like to replace it, but I haven't found anyone with a pre-made harness that matches the diagram I pulled up.

Has anyone made their own harness before? I assume the numbers are the wire gauges, and the letters are colors, but where is the color key chart so I know I'm getting the right one?