We're Open & Here For You! Important Coronavirus Information - Click Here to Learn More

Understanding the Colors of Electrical Wires: The Basics

Man fixing wires

When trying to understand your home’s electrical system, you may encounter a tangle of colored wires. Here’s what those colors mean, and a few things to keep in mind when checking your wiring system. If your home is older or you’re having difficulty with your home’s wiring system, we recommend you utilize a certified electrician.

  • What are Black Wires?
    First, you should always be aware of which wires may pose a safety hazard. Black, red, white with black or red tape will always indicate a hot wire. The term “hot” means these wires carry a live current from your electric panel to the destination. While white wiring is permitted— only when clearly marked with black or white tape—using any other color for a wire carrying current is strongly discouraged. This may pose a serious safety hazard that could result in death. Black or red wires always carry power from the service panel (breaker box) to your home’s devices.
  • What are Red Wires?
    Red wires are usually used as secondary hot wires. Red wires are also hot and should be clearly marked to avoid the dangers of electrocution. Red wires are commonly used when installing ceiling fans, where the light switch maybe.
  • What are Green Wires?
    Green insulated wires are often used for grounding. Ground screws on electrical devices are often painted green, too. Never use a green wire for any purpose other than for grounding, as this may pose a serious threat of electrocution for you or a professional working on your home’s electrical system.
  • What are White Wires?
    White or gray wires indicate neutral charged wires. However, neutral wires may carry power and pose a danger of electrocution if not handled properly. White and gray wires carry power back to the service panel. Both hot and neutral wires have the potential to shock and injure you if not handled properly.
  • What are Blue & Yellow Wires?
    Blue and yellow wires are sometimes used as hot wires. Blue wires are commonly used for travelers in three-way and four-way switch applications.

A multimeter will help you check and troubleshoot your home’s electrical wiring system. The multimeter can be used to check if there is an electric current flowing and how much. This can be especially useful if your home’s electrical system is old, outdated, or if you are unsure which wires may be hot or not.

If you need help with your electrical wiring, call Mister Sparky® of San Antonio at (210) 899-2430 and we’ll send one of our professionals to assist you.