I really love addons like 'Dark Background and Light Text', but they don't work with the 'New Tab', 'about:*' and addons.mozilla.org pages like most other addons in recent Firefox.
For the 'New Tab' page I now use 'New Tab Tools' to set the background to black. But I am still unhappy that its not possible to set all other pages to a dark theme.
Also that Vimium doesn't work with those pages is a shame as well. I hope Mozilla fixes that regression soon. Web Extensions should have the same abilities as the XUL extensions.
You can still tweak Firefox internals but you have to resort to its native `userChrome.css` [0] since current extensions API does not allow access to every corner. Luckily you can use devtools for that [1] what makes it quite pleasant (at least you don't have to restart browser to see the change). You can use pre-made package ([2][3]) and toggle what you want.
Thanks, but I do like it to be easily switchable. Some pages expect certain background colors and changing them makes embedded svgs hard or impossible to see.
Maybe you can get away with using the solarized theme, but I prefer having a black background...
For the 'New Tab' page I now use 'New Tab Tools' to set the background to black. But I am still unhappy that its not possible to set all other pages to a dark theme.
Also that Vimium doesn't work with those pages is a shame as well. I hope Mozilla fixes that regression soon. Web Extensions should have the same abilities as the XUL extensions.