House Wiring & Electrical Wire Colors

House Wiring & Electrical Wire Colors

Have you ever seen an action movie in which a character must (during a very tense, panicky, race-against-the-clock kind of moment) snip the right wire? The character is usually disarming a bomb or shutting down a security system. Whatever his or her intent, it’s always stressed that the color of the wire is critical. Snip the wrong wire and the bomb might blow up! Snip the right one and you can safely carry on. This sort of scene is very common in the fictional world, and it hinges on the character making the right choice when faced with a rainbow of colored wires.

Although you probably shouldn’t be cutting any of the wires in your house (unless you’re an experienced electrician, that is), you might have wondered about the home wire color code. Do all homes follow the same standard? If there is a standard home wire color code, is it followed worldwide? Read on to find out.

home wire color code


Home Wiring Colors

First of all, the home wire color code does differ between countries. For a detailed table depicting the wire color standards in various countries, please click here. We’re going to look at the United States only. To begin, let’s look at the basic facts:

Standard Wire Colors for Flexible Cables (extension cords, power cords, lamp cords)

  • Black = phases
  • White = neutral
  • Green = protective earth/ground

Standard Wire Colors for Fixed Cables (in-, on-, or behind-the-wall cables)

  • Black, Red, Blue, Brown, Orange, and Yellow = phases
  • White and Gray = neutral
  • Green and Bare Conductor = protective earth/ground
  • Green/Yellow Stripe = ground or isolated ground

The home wire color code was created for safety and convenience. It allows electrical workers to identify wires and work with them without risk. The color is used on the wire’s insulation and it is sometimes mandatory and sometimes optional. For example, one wire color that has become popular (and often mandatory) worldwide is the green- and yellow-striped wire insulation, which is used on grounding wires.

In older homes, the electrical wire colors may be outdated or the color might have faded or morphed over time, so caution is advised. Although there are differences between some homes’ electrical systems, these wires are most common:

Black: Black wires are used for power in circuits and they are usually hot (or live). They often run between a switch and an electrical load. Never attempt to use a black wire as a neutral or ground wire.

Red: Red wires are usually secondary live wires in circuits.

Blue and Yellow: Blue and yellow wires are usually live wires as well. You might find them on fans or lights, where they can assist a multi-way switch.

White and Gray: White and gray wires are almost always neutral. They can only be connected to other white and gray wires. White is much more common than gray.

Green: Green wires are grounding wires. They are there for safety, to direct currents into the ground when necessary.

– – – – –

Working with electrical wires in your home is very dangerous and could result in a fire or an electrical shock. If you live in (or near) Springfield, Missouri, and you need help with your home’s electrical system, call Complete Electrical Solutions at 417-831-8039. We would be happy to handle your electrical emergency and answer any questions you may have.