In electrical wiring, what color indicates a wire used mainly for three-way or four-way switch connections?

In electrical wiring, the color that typically indicates a wire used mainly for three-way or four-way switch connections is red. This color is conventionally used in many wiring systems to identify travelers in three-way switch setups. Travelers are the wires that connect two three-way switches, allowing the control of lighting fixtures from multiple locations. Understanding this color code is essential for proper installation and safety in electrical work, as it helps maintain consistency and prevent confusion during installation and troubleshooting.

Yellow wiring is often used for a different purpose, such as for switches or circuit runs, but it is not the standard designation for three-way or four-way switch connections. Using red for these specific connections ensures that anyone working on the wiring can easily identify the traveler wires amongst others such as black, which is typically used for the hot wire, and green, which is reserved for ground.