I use only these:
- black: offline with no external files, nothing special
- blue: see below
- yellow: default level when online
- orange: see below
- red: see below
Then I use a level behind if any of these things happens:
- the qube is interacting with other qubes, especially if receiving data, files
- the qube uses some applications not installed with the default distribution repos (depending on the method, it could immediately decrease the level to red)
- the qube downloads things on the web
- the qube is connected to some peripheral (i.e. a phone)