The preferred colours for AC phase conductors are: For a single AC phase: brown The colour combination green/yellow is always and exclusively used to identify the protective conductor. The various colored wires that you can see when you look behind a switch or an outlet are not an accident, but rather a safety feature that is built in. The IEC 60446 standard, “Basic and Safety Principles for Man-Machine Interface, Marking, and Identification,” establishes global guidelines for identifying electrical equipment terminals, conductors, and wiring colors. Proper identification prevents hazards, streamlines maintenance, and ensures. 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.
[PDF Version]