Chris brown new song where he's green
I think you might be thinking of Chris Brown's new song "Wobble Up" featuring Nicki Minaj, where he raps about being "green"!
"Wobble Up" is a single from Chris Brown's 2019 album "Indigo", and the lyrics do indeed reference him being "green" - but not literally green, more like being in a state of jealousy or envy.
If you're looking for a song where Chris Brown is literally singing about being green, I'm not aware of any specific song that fits that description. But if you're interested in exploring more of his music, I'd be happy to recommend some popular tracks or albums!