This doesn't work at all.
- For all of us looking for dark mode for dpf, there is a simple rough trick: --> add bookmark: --> URL: javascript:(function(){var el = typeof viewer !== 'undefined' ? viewer : document.body; el.style.filter = 'grayscale(0) invert(1) sepia(0) brightness(80%) contrast(80%)';})() --> Name: Invert --> and Save it. ;)
This trick can invert any page included "protected" pages (eg.Mozilla's, etc.).