Simple color change to green for enabled switch. Makes it easier to distinguish from disabled one.
Small changes concerning balance, gameplay, or graphics.
The retecture effect only seems to be applied to a button that's been wired. For consistancy and less user confusion an unconnected button should be recolored the same way to show whether it's on /off even though it's not affecting anything.
Just poking this one to bring attention to it again for the same reason as indicated by OP