The pairing name for the two main characters of the Halo series, the Master Chief and his A.I partner, Cortana. "Green and Blue" is also the name of a track in the Halo 4 Original Soundtrack.
**Spoilers**
The song plays at the end of the Halo 4 Campaign, where the Master Chief is seen in a blue bubble-like hardlight shield, and is confronted by Cortana, only to be told that she cannot accompany him away from The Composer, as the physical remains of her is down at the site of the debris from The Composer.
when you're holding up your phone and making faces at it, as though you are taking a selfie, but you're really taking a picture of the person across from you or the wall or anything else that seems interesting but you don't want to be caught dead taking a picture of.
This action is often made more convincing by wiggling the eyebrows or opening the mouth, to pretend you're trying to get a Snapchat filter to work.
FRIEND A: "Did you just take a stealthie of me?"
FRIEND B (turning phone around): "no I was just using snapchat's new filter, see?"