What Is the Meaning of the Colors in Residential Wiring?

Ground Wires

• Ground wires are not part of the conducting path and are not used to conduct electricity. Ground wires act as a safeguard, preventing electrocution. They are called ground wires because they are connected to the earth and protect against electric shock. Ground wires are required to be connect at the service panel, according to the U.S. National Electrical Code Article 250. A green or bare copper wire means the wire is a ground wire.

Neutral Wires

• Neutral wires carry return electricity back and serve as ground wires at the transformers. Neutral wires usually are indicated by a white wire, or a colored wire with a white stripe.

Live or Hot Wires

• Live wires, or hot wires, that carry electricity to the device in your home are designated by colors. Blue, yellow, red or black are some of the most common wire colors.

National Electrical Code

• The United States National Electrical Code (NEC) is the standard used in residential wiring. The code is updated every three years by the National Fire Protection Association (NFPA). The NFPA established the NEC as part of its initiative for fire prevention and reducing other safety hazards that could be caused by faulty wiring. The NFPA hosts webinars and sells copies of the code to educate the public about electrical wiring.