The mandatory colors for power wiring in the National Electrical Code (NEC) are Green, Bare, or Green/Yellow (a yellow stripe or band on green) for the protective ground (PG), and White (or alternatively Gray) for the neutral wire. This tutorial will discuss the wiring color codes for AC (single-phase and three-phase) and DC power systems based on the NEC and IEC standards. Many countries, including the UK (BS-7671), China, Russia, Hong Kong, Singapore, Ukraine, Belarus, Kazakhstan, Turkey, Israel, South Africa, Argentina. The standard electrical wire color code mandated by the National Electrical Code (NEC) is a critical safety system for licensed electricians. For typical building AC circuits (commonly up to 600 volts nominal), the NEC specifies identification rules for grounded conductors (neutral), requirements. Wire color codes are an international standard system that uses insulation colors to show the function, phase, or purpose of a wire. It works like a “language” for wires. With clear color differences, it ensures safety, efficiency, and accuracy in electrical installation, maintenance, and repair.