Internet Explorer 11 dark theme and dark mode for websites

Solution 1:

You might have luck with an addon (Tools -> Manage Add-Ons), if there's one there such as "Turn off the lights".

Otherwise, I hacked my own dark mode CSS file, which can be applied over the top of any website like so:

1. Go to Tools -> Internet Options -> Accessibility (under "Appearance" section)
2. If you click 'ignore colors specified on webpages', that affects all sorts of things including Development tools!, so instead, just click 'Format documents using my style sheet' and select your custom stylesheet

Here is my custom style sheet (create a new text file, and rename to name.css):

body:before { 
    content:"";
    position:fixed;
    top:50%; left: 50%;
    z-index:9999;
    width:1px; height: 1px;
    outline:2999px solid invert;
}

HT: Lea Verou

This will totally invert all colours in all text/images (IE9+ only). Much easier than trying to specify everything.

Else, if you have access to the site itself, you can use JavaScript to toggle some different styles (ask in Stack Overflow for how to).

Internet Explorer doesn't support @media (prefers-color-scheme: dark) (and can't access any Windows settings AFAIK) so this is why the only way programmatically forward is to use a button/toggle.