What color indicates the left side position light on civil aircraft?

In civil aviation, the color red is specifically designated for the left side position light on aircraft. This standard is part of international aviation regulations to ensure consistency and safety in identifying the orientation of an aircraft during both day and night operations. The left position light serves not only to indicate the aircraft's left side to other pilots and ground crew but also plays a critical role in collision avoidance, particularly during takeoff, landing, and in-flight operations.

By standardizing the left position light to red, it allows pilots, air traffic controllers, and other stakeholders to easily recognize the aircraft's heading. The use of colors is carefully designed—green for the right side, white for the tail light, and yellow is not designated for any standard position light—creating a clear visual difference that enhances safety in aviation operations.