Which color is used mainly as switch legs to fans and structural lights?

In electrical wiring, the color yellow is predominantly used to indicate switch legs for fans and structural lighting. This usage is standardized to enhance safety and prevent confusion during installation and repair. Yellow wires are often designated as the secondary wire that connects to a switch, allowing it to control a light fixture or fan by providing a pathway for current when the switch is turned on.

Using color codes consistently helps electricians and individuals working on electrical systems quickly identify the purpose of each wire, thereby minimizing the risk of errors that could lead to electrical hazards. In contrast, the other colors mentioned may have different specific uses, such as black typically being associated with hot wires or power sources, red often used for a secondary hot wire, and white generally reserved for neutral wires.