Sounds like a Gorillaz song to me. I found this remix on Limewire apparently called "Green World (Drinking All the Sunshine)" with Cee Lo and ~rumoured~ Bootie Brown after trying to download the original "O Green World" like most others. Limewire was a free peer-to-peer file sharing program and I downloaded a lot of music from there in the mid-2000s. This remix was most likely made by a fan.

"A Rappy Song" from Damon Albarn's album "Democrazy" remixed by a fan feat. Cee Lo Green and an unknown artist.