What colors are acceptable for stop lamps?

The acceptable colors for stop lamps are red or amber. These colors are specifically chosen for their visibility and their ability to signal intent effectively to other road users. Red, being a universally recognized color for stopping or caution, ensures that drivers and pedestrians can quickly identify when a vehicle is decelerating or halting. Amber can be used in combination with other lighting signals to provide additional alerts, but both colors are mandated by regulations to enhance road safety.

The other options contain colors that do not conform to the standards for stop lamps. For instance, blue or white can be associated with emergency vehicles or other signaling purposes but are not used for stop lamps in conventional traffic situations. Green or yellow colors do not provide the same immediate recognition needed for stopping, and purple or pink are not recognized as signaling colors in traffic safety. Therefore, red and amber stand out as the appropriate hues for ensuring clear communication on the roadway.