The correct legend of covers LEDs seems to be:
Top one:
- Red: Mobile network is not available
- Purple blinking: Mobile data is not available
Bottom one:
- Red: On charge
- Yellow: On charge, almost charged
- Green: On charge, fully charged
- Yellow blinking: Missed call
Fingerprint scanner:
- Both red: Device is locked
- Both blue: Device is unlocked, both buttons functional.
- Left one is green, right one is red: incoming call, press left to answer, right to reject.
- Left and right blink in turn: media playing