What a beautiful little boy! I would say his mutation is Olive green dominant pied spangle sf violet Do you see the bluishness by his rump? That usually indicates sf violet, or he's split for blue, which will fade after his first moult. But it looks strong enough to be SF violet.
He's absolutely stunning! The first name that came to mind was Figaro He also looks like a Tucker, Irving or Harlequin.
I made a thread with unique budgie names sorted by color and gender, so feel free to look on there for ideas