10 Electrical Wire Colors and What They Actually Mean

Green, Green-Yellow and Bare

According to Mark Dawson, chief operating officer of Mister Sparky, “green insulated wires are used for grounding.” Green is the most common ground wire color, but “green-yellow” (green wire with a yellow stripe) and “bare” wire (copper wire without colored insulation) can also be used.

Ground wires reduce the risk of electrical overload and fires by redirecting excessive electricity during a short circuit or similar fault. Consequently, they can conduct electricity and should be handled with caution. “Never use a green wire for any purpose other than for grounding, as this may pose a serious threat of electrocution,” Dawson says.

Older homes with”knob and tube” (K&T) wiring only have a black “hot” wire and white “neutral” wire, without any ground wire. “This older type of wiring does not provide a ground for modern appliances, which can lead to damage to the appliance or even worse — injury or death,” says Dawson. If you discover this type of system while performing electrical work in your home, Dawson recommends replacement because “there is no way to make this type of wiring safe.”