If you're tired of watching bright-lit videos and being constantly distracted by their garish color scheme, you can now rest your eyes. The latest version of the Dark Mode extension adds black as an option as well as a simple way to turn off YouTube's screen. You can install the newest version of the extension from Chrome Web Store and make changes on a persistent basis.

After you install the Dark Mode, just click the button at the top left corner of Youtube to turn dark mode on/off.