Comment 4 for bug 1338132

This is essentially bug https://bugs.launchpad.net/light-themes/+bug/829218 from back in the day.

Another example is here http://www.webupd8.org/2011/12/light-themes-evolved-ambiance-and.html

I haven't looked at in ages, but I seem to remember my solution was more elegant than the light-themes-evolved one (which I started with). It's something else I can dig out if there is interest in it.