Electrical Wire Colors: Deciphering What Each Color Means

The electrical wires that bind your home together come in an array of colors that specify each wire function in a circuit. But what does each one mean?

Fortunately, the color coatings around the copper conductor of the wire give you all the clues you need to know as to what each wire does and whether it’s hot, neutral, or ground.

This is incredibly important to know before you start any kind of home wiring project, as well as essential to your safety, so let’s explore what these colored wires mean and when to use them.

Black Electrical Wires

Black electrical wires carry the current from the power source to the outlet and used for power in all types of circuits. Make sure you use extra caution when dealing with these - when you see a black wire, you know it is hot. Any circuit’s black wire should be considered live at all times.

These wires are often used as a switch leg that transfers power to switches and outlets in all circuits. Black wires are never used for a ground or neutral wire and are meant to be used as the power feed for a switch or an outlet. They are most commonly found in residential buildings.

Red Electrical Wires

Red electrical wires are the secondary live wires in 220-volt circuits and are commonly found in a sheathed, multi-conductor cable. These wires are typically used for switch wiring as well as the interconnection between smoke detectors hard-wired into the power system.

You can link two red wires together, or you can link a red wire to a black wire. Since red wires conduct current, they are considered hot.

Blue and Yellow Electrical Wires

Blue and yellow wires are most commonly found in commercial buildings and are used as the live wires pulled through a conduit. These wires carry power but aren’t used in typical outlet wiring. They’re used in more complicated circuits and are used as hot wires to conduct current between switches and poles, therefore known as travelers.

Yellow wires are used as switch legs to ceiling fans, structural lights, and outlets paired with light switches, while blue wires are usually used as travelers for three-or-four-way switches.

White and Gray Electrical Wires

The colors white and gray indicate a neutral wire. That means it connects to an electrical panel’s neutral bus bar.

Once power leaves the electrical panel through the hot wire of a circuit and works through devices such as a light bulb or an outlet, the electrical current returns back to the service panel through the neutral (and usually white) wire that is connected to the neutral bus bar, which returns the current to the electric utility grid.

White wires are typically found in residential buildings while gray ones can be found in commercial settings. White and gray wires can only be connected to other white and gray wires.

Although neutral, these wires still may carry a current, especially an unbalanced load, so handle with caution. If you see a white wire marked with black or red (or a piece of black or red electrical tape at its ends), that means it’s acting as a hot wire and is no longer neutral.

Green Electrical Wires

Green wires connect to the grounding terminal in an outlet box and run to the ground bus bar in an electrical panel. Their primary purpose is to ground an electrical circuit and provide a path to ground for a circuit’s electric current if a live wire within the circuit interacts metal of another conductive material.

These wires only connect to other green wires and act as a failsafe, allowing for electricity to have a place to escape. They can carry significant current, so treat them cautiously.

Other Colored Wires

These are the most common colors used in electrical wiring. Other color combinations, such as striped wires, may be used for other applications.

Remember, black and red wires are always hot, meaning they are source wires that carry power from the electric service panel to a destination, such as an outlet or a light. White wires augmented with red or black tape or markings are used as hot; however, a black wire can never be used as a neutral or ground wire, or for any purpose other than to carry a live electrical load.

Blue and yellow wires are sometimes used as hot wires and as travelers, green wires (and bare copper wires) are ground wires, and white and gray wires are neutral. However, all electrical wires, regardless of their function, may carry an electrical current at some point and should be treated with equal caution.

We hope this list helps you differentiate between the colored wires in your home. If you are unsure of what any of these wires mean and what they do, it is important that you seek a qualified professional to answer any questions you may have.

While DIY options are feasible, dealing with the electrical issues in your home can be an overwhelming task. Here at Pacman Electric, we are committed to lighting up your life in as dynamic a way as we can.

Contact us today or give us a ring at (954) 577-7924. we look forward to helping!

Chris Pacchioli