This doesn't seem to be working for me. It would be really nice if there was a right click to turn this off or on like the old Simple Night Mode use to work. I can get this to turn dark sometimes, but iffy.

Image previews do not display properly but there is no way to whitelist them globally.

Also, the addon makes the browser lag unbearably when moving the sliders with many tabs open.

+ inverse colours and dim function
+ rather nice interface
- inverse colours doesn't always mean proper night colours
- doesn't work on all sites (e.g., the Firefox start page, random sites)
- can cause slow down (e.g., on video sites)