Wow I really like the idea of this... you've almost pulled it off.
If you're going to use the three colours yellow, orange, green. Then you should try to tie them together for example, having icons of all three colours. Editing the wallpaper with a gradient of the 3 colours. Or edit the system meters colours.
You wouldn't have to do all of that, but doing one or two, would help all the elements to fit together and make an AWESOME screenshot