YouTube Has A New Dark Mode: Here's How To Get It
Enabling the mode is fairly simple, provided you're using an up-to-date Chrome browser.
Toggle "Dark Mode" on and you're settled. If you have the most recent download of Google Chrome, hit control + shift + I (Windows) or option + command + I (Mac).
"In the table that opens there should be a row named "VISITOR_INFO1_LIVE", double click the "value" cell and replace it with this code: fPQ4jCL6EiE then press enter". That'll open the developer window on the right.
That's it, you now have an experimental dark mode available to you. At this point, YouTube will still be white but there may be other changes to how the page looks.
That said, you're welcome to enable "dark mode" any time you want, if you prefer the contrast provided by its color scheme. Once that's done, all you'll need to do is reload the page, click your avatar, and dark mode should load up.
The built-in mode was discovered on Thursday and shared in a Reddit post, and while the setting doesn't appear by default, a quick command in the developer console is all that's required to enable it.
Whether YouTube will make this feature official sooner rather than later remains to be seen.