Love this idea, but as a work around since this is an older request. I'd recommend downloading a night mode extension to your browser. I hope they do consider that as an option. But I know once you login your settings are saved.

Alternatively, there can be an option in the user's settings to set your default for when you're logged in. People can still toggle the mode but the default is customizable on the profile.

Please Twitch, implement that!

+1 for this! It's super trivial to implement and is a great way to improve the UI. Twitch is one of the only websites I regularly use that does not support this.

It's easy to implement as these 3 lines of JavaScript:

const instanceDarkMode = matchMedia("(prefers-color-scheme: dark)");
let isDark = instanceDarkMode.matches;
instanceDarkMode.onchange = ({ matches }) => {
isDark = matches;
};

I like this idea, but I can understand why this isn't a good idea. Someone that is blind, or partially blind, could have trouble seeing the lettering on the dark screen, and would need the contrast of lettering on the white background, in order to make out the words.

Perhaps, when you sign up for the platform, after you pick your username, the next thing you pick is "would you like to be in light mode or dark mode (can be changed later in Settings)"? And they leave in that mode across every page you access, be it a Twitch stream or the main page.

Because, frankly, going from seeing a twitch stream that's in dark mode... to being on the main page, and having the bright-white background searing my corneas... is a little painful. And the fact that Twitch hasn't gotten that much figured out is a rather glaring oversight.

A theme option may be offered with the color scheme of the device's operating system. Thus, if the device switches to dark theme in the night, Twitch also switches to dark theme. Example: YouTube