Blackberry Indicator Lights Defined
The LED indicator blinks red whenever you have incoming/waiting communication messages on your phone – new email, new call/missed call, new BlackBerry Messenger message, new SMS, etc.
Coverage Indicator light. This lets you know you are connected to a network.
If you wish to turn off the Blinking Green light Go to Options > Screen/Keyboard and turn LED Coverage Indicator to Off.
Lets you know your phone is connected to a Bluetooth device, such as a Bluetooth headset.
A blinking yellow light means it is time to charge your BlackBerry as you are running low on battery power.