Teamed up to pull many a wire in the old central offices to identify which wire to move to fix a trouble report or move a telephone number to a new location. Of course, nowadays the process has been made obsolete by electronic/virtual switches.
BTW if we'd had a hand in making the wire runs that sloppy, the chief switchman woulda had a hissy fit.
There is still plenty of hard-wired equipment out there. Way too many to color-code in many cases, but they do tend to be labeled at both terminals.
Still not nearly as elegant as the wiring found in old power substations that date back to the 1910-1940 period. The old Lake Shore plant electrical house had some absolutely awesome wiring on the back of the control and relay panels, with each individual wire pulled perfectly straight, and all turns at exactly 90 degrees, never crossing other wires. I wish I had pictures.
It also had asbestos in the insulation, but that was the standard back then.