What color lights are commonly associated with emergency vehicles?

The colors red and blue are commonly recognized as standard colors for emergency vehicle lights in many areas. Red lights are often used for vehicles such as fire trucks and ambulances, primarily to denote caution and alert other motorists to yield. Blue lights are commonly associated with police vehicles and serve a dual purpose: signaling authority and alerting the public to the presence of law enforcement. The combination of red and blue is particularly effective in attracting attention and differentiating emergency vehicles from regular traffic, as they stand out in a variety of environmental conditions and times of day.

In addition to their visibility, these colors have been standardized in various jurisdictions for clear identification of emergency services, which aids in public safety and situational awareness during emergencies. Other color combinations, such as white and yellow or green and orange, do not carry the same established recognition and purpose in the context of emergency response, which helps explain their absence from common usage in emergency vehicle lighting.