How to invert color of one window?

I use PDF books to learn programming stuff; therefore always a PDF file with white background and a dark-themed editor are open simultaneously at the same desktop. So it would be a good idea that I could invert the color of that bright window.
Any help is appreciated.

There are two ways you can do this:

  1. Open the PDF in Okular, and use its built-in tools: Settings > Configure Okular > Accessibility > change colors > and then choose your preferred method of color inversion. You can also customize the toolbar to add a button to quickly toggle this on and off
  2. Enable the systemwide “Invert” feature in System Settings > Window Management > Desktop Effects > Invert. Then press Meta+Ctrl+U to invert only the focused window.
4 Likes

i did not know this was on a per window basis (wasn’t clear from the description), so i always left that plugin disabled…

this is an awesome feature and should probably be on be default.