How to turn on Firefox dark theme without telling websites to turn dark?

I like Firefox's dark theme, but I don't like Firefox passing the theme info to many websites (e.g., Google, YouTube, etc.). How can I stop Firefox from doing this without changing the skin to the light theme?

Solution 1:

As per this Reddit answer:

Old thread but it turns out in google - the current way to do this is to set "layout.css.prefers-color-scheme.content-override" to 1 (0 - dark mode, 1 - light mode, 2 - system colors?, 3 - theme colors?)

Having faced the same problem with the newest Firefox version, I can confirm this works. Just set layout.css.prefers-color-scheme.content-override to 1 in about:config and web sites will appear in light mode.