In brief: Mercedes-Benz has become the first automaker in the US to receive permits allowing the use of turquoise-colored lights on the outside of vehicles to denote an autonomous driving system.

Most street legal vehicles utilize a combination of three colored lights: white for headlights and reverse lights, red for tail and brake lights, and orange for blinkers. Other colors, like dark blue, are reserved for police use. Now, Mercedes-Benz will be bringing turquoise to highways in California and Nevada.

In California, the permit will let Mercedes-Benz trial turquoise lights on test vehicles for two years. In Nevada, the automaker can start adding the feature to 2026 year production vehicles.

Also read: The State of Self-Driving Cars: Autonomous Advances

The turquoise lights will illuminate when Drive Pilot is engaged. Mercedes-Benz Drive Pilot is a Level 3 advanced driving assistance system (ADAS) that can only be used in limited situations and in certain (geo-fenced) areas, like in heavy traffic on select highways at speeds of 40 MPH or less. Drive Pilot is also limited to daytime use and during clear weather, and cannot be used in construction zones. Furthermore, the driver is not allowed to fall asleep or leave the driver's seat.

As a Level 3 system, the driver is permitted to take their hands off the wheel, their feet off the pedals, and divert their attention away from the road. Most other driving systems require you to keep your hands on the wheel and pay attention. With Drive Pilot engaged, users are free to browse the Internet or watch videos on the vehicle's central display.

The turquoise markers will alert other drivers to the fact that your vehicle is driving itself, so hopefully they won't be alarmed if they see you doing other things while behind the wheel.

Mercedes-Benz said numerous studies have proven that turquoise is the optimal color for automated driving, as "both physiological and psychological factors attest to higher values in almost all areas with turquoise rather than with other colors." Turquoise also adheres to the SAE J3134 Recommended Practice guidelines.

Mercedes-Benz said Drive Pilot-equipped EQS Sedan and S-Class models will be available in early 2024 through participating dealers in California and Nevada.