Aviation Colour Codes
Aviation Colour Codes are based on four colours and are intended for quick reference only in the international civil aviation community; they are part of the ICAO International Airways Volcano Watch system (IAVW). The Aviation Colour Code reflects conditions at or near a volcano and are not intended to pertain to hazards posed at a distance or downwind by drifting ash. The codes range from GREEN to RED.
| ICAO Colour Code | Status of Volcano's Activity |
|---|---|
| GREEN | Volcano is in normal, non-eruptive state. Or, after a change from a higher level: Volcanic activity considered to have ceased, and volcano reverted to its normal, non-eruptive state. |
| YELLOW | Volcano is experiencing signs of elevated unrest above known background levels. Or, after a change from higher level: Volcanic activity has decreased significantly but continues to be closely monitored for possible renewed increase. |
| ORANGE | Volcano is exhibiting heightened unrest with increased likelihood of eruption. Or: Volcanic eruption is underway with no or minor ash emission. |
| RED | Eruption is forecast to be imminent with significant emission of ash into the atmosphere likely. Or: Eruption is underway with significant emission of ash into the atmosphere. |
