What do the colors on the volcanic display mean?

The colors of the Volcano display depend on the activity level and you can read further about these at the below links:

https://wovo.iavceivolcano.org/volcanic-alert-levels?layout=edit&id=15

https://www.usgs.gov/observatories/hvo/news/volcano-watch-what-are-volcano-alert-level-and-aviation-color-code

You can also interpret the colors based on the ash polygon colors as described below:

Volcanic ash polygon colors:

- Gray: the current ash area

- Green: the first forecasted ash area (usually +6 hours)

- Yellow: the second forecasted ash area (usually +12 hours)

- Red: the third forecasted ash area (usually +18 hours)