What do the different colours of the LED indicate?

Flashing Red – Low Battery warning less than 15% Battery level.
Solid Red – Battery level is below 15% and currently being charged.
Solid Orange – Battery level is between 15% and 90% and currently being charged.
Solid Green – Battery level is above 90% and currently being charged.
Flashing Blue – Indicates a notification has been received (Message unread, missed call, email etc).