What does the color yellow signify on airfield markings?

The color yellow on airfield markings signifies caution, which is crucial for maintaining safety on the airfield. Yellow markings are typically used to indicate the start of a taxiway or runway, guiding pilots and vehicle operators to navigate the area safely. This color prompts attention and awareness, alerting individuals to potential hazards or important instructions, such as where to taxi or where to be cautious.

In contrast, other options convey different meanings that do not align with standard aviation signaling. For example, marking indicating danger and a need to stop immediately would generally be represented by red markings, while an indication of "All clear" would suggest a green color for safety and go-ahead, and a no-entry zone may be represented by a clear visual or symbol rather than a specific color. Understanding these color codes is essential for safe operations within the airfield environment, which relies on clear visual communication among diverse activities involving aircraft and vehicles.