One blue and one red LED means that “Do Not Disturb” is enabled. This means that no callers can reach you, with exception of urgent calls if you have urgent calls enabled. For more on urgent call settings click here.
You know “Do Not Disturb” is enabled if the button is black with white writing. You can disable this setting in the imp app by going to the “Devices” page.
On the same “devices” page, you also have settings for “Allow All Calls,” which allows both Greenlist and Greylist callers to ring your phone. Redlisted numbers will still be blocked.
Click here to see the full LED guide.