Electrical wire colors probably don’t mean anything to the average homeowner, but those distinctions are actually very important and knowing the proper color coding is essential when performing electrical work. Each color serves a different purpose and you should be aware that all wires, no matter their function or color, can carry a current at some point so they should be handled carefully.
In 1881, the New York Board of Fire Underwriters issued the first set of safety guidelines for electrical wiring. In 1893 the first National Code of Rules for Wiring Buildings for Electric Light and Power was created and in 1897 the NBFU produced the first National Electrical Code but colors weren’t addressed. Wire color codes were finally mentioned in the 1928 edition of the NEC.
*The basic guidelines below apply to electrical wiring in the United States, though there are a few exceptions, so calling a certified electrician is your safest option.*
Green, green with a yellow stripe, or bare copper
These are ground wires that keep you, your appliances, and your home safe from electrical fires. Their purpose is to provide a path for a circuit’s electrical current if a device shorts out or trips a breaker.
Black
Black indicates a hot or live wire that’s carrying a current and is used for power in all circuits. These wires feed an outlet or switch and are often used as switch legs (the connection that runs from the switch to the electrical load).
Red
This will be your second hot wire when doing a 220-volt installation for large appliances such as a stove, clothes dryer, or air conditioner. Red can also be the interconnecting electrical wire between two hardwired smoke detectors.
Blue & Yellow
These two colors are hot wires usually pulled in conduit for common plug-in electrical devices. Blue wires are used as travelers, usually on three- or four-way switches (controlling a light from multiple locations) or as switch legs for things such as fans or lights. Yellow wires are almost always used as switch legs for outlets, fans, or lights.
White or Gray
White or gray indicates a neutral wire, which provides the return path for the current carried by the hot wires and is grounded within the electrical panel.
Wow, good to know the different colors mean different things. This proves that I should hire an electrician. I’d probably burn my house down if I tried the wiring by myself.
That is not to say that you cannot use different colors for different things. Essentially the colors don’t matter as long as you match the appropriate color at one end with the matching color at the other end. A lot of diagrams will tell you that orange means TXD or that blue means GND, etc etc. where in reality they truly have no definition every color is just a standard copper wire sending a signal from one end to the other as a slave. So you could literally, completely disassemble any braided cord that you wanted to and re-utilize it for any other device that you wanted to. The only thing that you need to remember is that you need to match one end to the other end of the same color. Essentially the colors are not encoded or programmed to do any one specific functionality. They are just a grouping of copper wires that will receive and transmit a signal down a line at the mercy of the device which they’re connected to. A wire is what you make it.
This is great! The quickest way to identify house electrical wiring is by its color. A number of different colors may be used for the hot wire in various types of switch wiring. Thanks for sharing.
My husband is trying to replace a garbage disposal. The power cord that he disconnected from the old one only has 2 black wires and he’s not sure which of the 2 connect to the black and white ones on the new disposal. Please help
Nina – your best bet is to call a professional local electrician.
Great explanation for the DIYer. Most electricians will follow the standardized format for wiring a building so, in most cases, following this guide will make any electrical project a lot easier. Just remember to kill the main power to any circuit that’s being worked on. 120 volts is a bit more than a tickle and 230 volts is a serious kick in the huevos
This is a fun article to share with customers as well. Electricity in the home is an area with a lot of mystery surrounding it, to the average homeowner. And it’s always great to have resources to share with them to help build trust and credibility. Thank you for the post!
Changing ceiling fan. There are only a white and brown wire coming from the ceiling. I want confirmation that the brown is in place of the live black.
I recently did a smart home and all their lightning was home automated. I guess you could say the high voltage is smart. Was the most difficult job I ever seen.
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I am installing a ceiling fan. the ceiling has a black wire a white wire and a red wire and a ground wire. In the manual it has the black to black, white to white it has a blue wire and not showing the red. Can the red also mean blue in this case? I have a dual switch.
Excellent writing! We can take away a lot of important information from this article. Keep sharing great posts.
It is easy to recognize which is which with colored wires