YouTube enabled dark mode on the web right alongside its big Material Design makeover way back in 2017. But the only way to get it working until now was to toggle the dark theme on or off manually. With more and more web browsers adding native support for these color schemes, YouTube is now tapping into the underlying API to give you the ability to match its website with your browser’s theme.
YouTube's theme setting for the web interface has been tweaked a bit to replace the toggle switch with three options. With the new Use device theme choice, YouTube will match your browser, which should come handy if your browser follows a time-based dark mode trigger.
The redesigned drop-down menu looks to be live for everyone, and it worked just fine on a variety of browsers in our testing. You can give it a try by clicking on your account avatar and going to the Appearance setting, as shown in the screenshots above.
Thanks: Kinetic Screen