You're probably right, I'm still trying to figure out how to express this idea properly.

I like the good old fashioned red and green on your example, but I feel any toggleable control should have two two-axis modes: unpressed/pressed, and on/off (e.g. in Cocoa Touch, UIButton can be highlighted, and/or selected), which is typically difficult to convey with flat shapes and colour alone. If you can do it, awesome.