My grandfather was color blind, but I'm not. My mother had to sew little tags into all his clothes so he knew what to wear.
Thinking along those lines, I just spent a week down in WVa working on a bunch of school HVAC systems. I noticed that the wiring harnesses on most of the <recent> mechanical equipment is wired with one type of wire, say red, with a little number sticker-tag to identify and cross-reference them with the wiring schematic. I bet you can get sheets of those numbers at an electrical supply house. Then, anytime you work on the wiring, add the stickers as you go and cross-reference them on a copy of the schematic. Or make it a winter project; pull a connector, clean it, identify it and reconnect...