Simple and lazy invert color script that can be used anywhere. Codes other than scripts/content.js are (partly) from chrome tutorial with some modification. This one inverts background images, but does not invert other images (<img>) and <video> tag. Another version if this one does not work on some websites https://github.com/lvsl123/chrome-extension-invert-color-2

So far this one works on most sites but not all of them. All source codes are open to the public in case safety is your concern.

All you need to do is download the whole zip file. Unzip and find a folder to put them, and go to chrome://extensions . Choose developer mode on the top right, and choose the folder where the extension is unzipped. Does not work on mobile Chrome

I can't guarantee anything else here and this is not completely bug free. If this one does not work on one page I use the other one above.