Of course the F-keys still have their normal functions, presumably.
The Fn Functions appear to be:
F1: Internet Media Key
F2: Back. However the behaviour you mentioned paired with it's different colouring, I don't know.
F3: Sleep
F4: Eject
F5: Play/Pause
F6: Stop
F7: Skip Backwards
F8: Skip Forwards
Your second pic shows some additional media keys, such as Volume down, volume up, and Mute. the "LVT" key is a special key that is probably only recognized by Lenovo machines and possibly only laptops.
The indicators below are from Left to right, Num lock, Caps lock, and Scroll Lock.