new {undisclosed} feature

At the same time I'm looking at the way we identify various button actions.
These fall into two groups:
Actions, that change a switch, setting, etc.
Links, that open a different window.
An outlier is the grey 'Close' button which sometimes just closes a window, but
other times can re-open a previous one with a RH mouse click.
Unfortunately most of these have the same pale blue, while some are pale green -
the same colour as the section panels. Also a few link buttons are grey (such as
those in the kit window).
While we try to avoid major changes to the UI I think it would be an idea to
rationalise these. We can do this partly by colour, but also possibly with the
button style.
I would suggest that nothing except actual section panels should be that pale
green, beyond that I'd very much like a consensus, so please take a look and
give your opinions.
If you don't have Yoshimi, a quick look through the user guide will make this clear.
http://yoshimi.github.io/docs/user-guide/