What does LED indicator convey in Samsung Galaxy S4(GT-I9500)?

Samsung Galaxy S4 has an LED indicator in the top-right corner on the front of your device. The LED indicator notifies you of a missed Notification, Low battery, when the device is Charging, or when you are Voice recording.

The following are the types of events and their associated color:

Blue:
•Pulses in multi-color blue while the device is turning On or Off.
•Blinks blue for a missed call, message, or other notification.
•Blinks blue when you are recording voice.

Red:
• Glows red when the device is connected to a charger and is charging.
• Blinks red when the device is connected to a charger but there is a problem with charging.
• Blinks red when the battery is low.

Green:
• Glows green when the device is connected to a charger and the battery is fully charged.

NOTE: LED will light up only when the screen is off.

Click here to know how to enable Notification lights in Samsung Galaxy S4 (GT-I9500).