You've linked your Wave, Wave Mini or Wave Plus to the Airthings Hub successfully, but when you wave your hand across the monitors, they no longer show a color, and there is a white ring instead.
This is an issue that affects select users based on the firmware and version of the app that is used, but don't worry, because:
...there is an easy fix!
To get your color back, follow these steps:
Go to your app, Settings > Devices > Select the Wave monitor > Select glow light indicator. Follow the steps to reset your glow light indicator in the app.
If step 1 did not work, follow steps 3-7.
Unpair from this device (NB: this will start a fresh measurement! However your past measurements will still be available on the online dashboard).
Unplug your Airthings Hub
Unpair then repair your Wave monitor with the app.
Plug in the Airthings Hub.
Link the newly paired device with the Hub again, and the color ring should now work.