My Air 2, which we got today, has a slight spine along the middle left side when the iPad is in portrait, but as I keep the iPad mostly in Landscape with buttons down I dont notice it. Hopefully I'll forget about it soon until I next use a white page in portrait 
The keyboard mostly looks evenly colored (the white does, the grey seems a darker on the left but that is I think a by product of the keyboard been semi translucent)
The keyboard mostly looks evenly colored (the white does, the grey seems a darker on the left but that is I think a by product of the keyboard been semi translucent)