Improve "Night Mode" colours for epubs (currently it inverts image colors)
The current "Night Mode" sets a black background and then uses CSS to invert all of the colours. That's pretty much workable on text-only ebooks, BUT it doesn't work so well with some colours or with images.
Night mode CBR (rendered by evince):
It's not just an image problem, though, as some reasonable headers can become quite bright: