Hi, I'm trying to get as much as possible of firefox to use dark theme to save my eyes at night. I use https://addons.mozilla.org/en-US/firefox/addon/darkreader/ to customize the sites automatically and it does an excellent job, except that firefox pages can't be customized with it and by that I mean: about:blank about:newtab about:config about:preferences for the blank and newtab pages I found three solutions: 1- create a [userContent.css](http://kb.mozillazine.org/UserContent.css) file with the following @-moz-document url-prefix(about:blank) {*{background-color:#000000;}} @-moz-document url-prefix(about:newtab) {*{background-color:#000000;}} 2- go to about:config and change browser.display.background_color to #000000 browser.display.foreground_color to #ffffff 3- Go to "Preferences" and search for "colors" click on the colors button and set the background and text colors to the same colors as in 2. now I tried all of the solutions above and all of them have side effects, the most prominent and annoying one is flashing white page for a couple of seconds when opening a new tab or white page while the website, other annoyances is that the settings don't apply to about:config and about:preferences even if I add them in userContent.css -To test the flashing white you only need to open a new tab (while applying my settings above) and you will see it. -To the white page before the site is loaded you need to open the link from another page(if you open a new tab and then paste the link you won't get the white page since the about:blank or about:newtab will have the dark background) so to see my problem do the following: 1- go to https://github.com/biesiad/deelay#deelayme 2- right click on deelay.me link and click "open link in a new tab" the link will be opened in a new tab that has the background in white or grayish color. How can I solve these problems ? any tip would be appreciated. Regards