Notification bar turns green when I'm having a phone call (Galaxy S4 Plus)? Whenever I talk to someone and the Phone app and the phone call in progress is not in the foreground, the entire Notification bar turns all green on me. See the screenshots below. When I return to the phone call it disappears (i.e. turns back to normal/black).





Is this normal? What does it mean then? Does this happen to any one of you with a Galaxy S4? Is it a bug? If this is a "feature" of the phone, how can I get rid of it? I've looked at settings but couldn't find anything relevant.

The phone is a Galaxy S4 Plus (GT-I9506) on Android 4.2.2 (stock ROM and everything, brand new, retail version, unlocked).
The green is a notification that you're still on a call.