What color must the back turn signals be?

The back turn signals on a vehicle must be red or amber. This is a requirement that ensures visibility and clarity for drivers behind the vehicle when signaling a turn or a lane change. The use of red or amber colors is effectively standardized across many jurisdictions, including Texas, to minimize confusion on the road.

Red signals are often reserved for brake lights, while amber lights are commonly used for turn signals because they are bright and attention-grabbing. This distinction helps communicate the driver's intention clearly to other road users, thereby enhancing safety. Red may also enhance visibility in low-light conditions, making it easier for other drivers to notice the signaling vehicle.

Other colors, such as white or blue, do not provide the necessary clarity and may be used for different lighting purposes, like reverse lights or emergency vehicles, respectively. Yellow or green are not accepted for turn signals as they do not fall within the required safety parameters for signaling.