Prevent Firefox from blinding you when opening new tabs

README.md

I use Darkreader to give any website a dark mode, which I highly recommend. Even with this plugin, there are breif moments when opening links, that the browser displays an entirely white screen. Thankfully, this can be mitigated!

1. Enable toolkit.legacyUserProfileCustomizations.stylesheets in about:config
2. Create a folder, /chrome/, in your Firefox profile folder

• You can find the folder by going to about:support
• On Windows: C:\Users\<user>\AppData\Roaming\Mozilla\Firefox\Profiles\<profile>.default-release\chrome\userChrome.css

3. Add the following .css files.
4. Restart Firefox
5. Test it out by going to about:blank

Note: You can edit the hex values to your liking. I used the background color of the new tab page.

userChrome.css

#browser vbox#appcontent tabbrowser, #content, #tabbrowser-tabpanels, browser[type=content-primary], browser[type=content] > html {
    background: #2b2a33 !important;
}

userContent.css

@-moz-document url(about:blank), url(about:newtab) {
    #newtab-window, html:not(#ublock0-epicker) {
        background: #2b2a33 !important;
    }
}

Sources:

• cml-99 @ reddit
• enigma @ stack overflow