Easiest Way to Switch Between Light and Dark Mode Per Site

Most people want dark mode on reading sites and normal colors on a few others, such as design tools or shops.

Modern Dark Mode is on for every site by default. To keep a site light, open the extension's popup on that site and tick "Exclude this site"; the page reloads in its normal colors, and the extension remembers it from then on. Untick it to make the site dark again. Exclusions go by the exact site address, so a subdomain such as shop.example.com is set separately from example.com. There's no mode where only chosen sites are dark.