This question is not stemming from any immediate practical application. But I am curious about the color of wire insulation used for three phase 208V or 240V well pumps. Looking online I see a lot of submersible well pump cables that are black/red/yellow/green. But I don't see any that are black/red/blue/green. I know black/red/blue/green colors are somewhat customary (but not mandatory) for 208V. Also white if neutral is used.
Is it an electrical code requirement in the US to use wire listed as submersible well pump wire under UL 83 for well pumps? What part of the NEC calls that out? I am talking about the wire that goes down the bore to the pump motor.
I know the NEC is silent about colors, but what is the customary color, if any, of insulation used for 3-phase well pump wire and cable (208-240V)?