I am JUST barely trying to learn. So from what I read today, to me it seems to be a dominant pied green budgie. The dominant pied variety has a clear zone across the bottom of the wings. The band across the dominant pied's wings and belly can be very large. The band across the dominant pied's wings and belly can also be very small. Also the band on the body can be irregular, like your bird above. As most of them said a picture of his back. However do NOT take my word for it. Wait for other's to comment on it.
Shelly is right, from what can be see the bird on the right has the characteristics of a dominant pied. Body colour high on the chest is usually a sigh of a dominant pied but we need a back picture to be sure. The other bird looks cinnamon light green