Hello Tom - Here's the link describing the Aviation Color Code and the Alert Level: http://volcanoes.usgs.gov/activity/alertsystem/index.php Additionally, the "Current Activity" page of each volcano has a short description of the volcano's current code in the lower-left section of the page (https://www.avo.alaska.edu/activity/Pavlof.php ) Thank you, Cheryl -------- Tom Kopaceski wrote: What does the different colors represent? -- Cheryl Cameron Geologist, Alaska Volcano Observatory Alaska Division of Geological & Geophysical Surveys voice: 907-451-5012 fax: 907-451-5050