This extension makes YouTube website look much easier on your eyes at night time. It adds a nice dark theme to YouTube with a smooth black background. a. Automatically sets a dark theme for all YouTube pages. b. Has an in-page switch button (at top-right corner in YouTube website) to turn the dark theme ON or OFF. c. The addon has two dark themes. Theme (A) uses standard CSS techniques to darken the YouTube page. Theme (B) uses CSS filters to do this job. (use the in-page button to switch between these two themes). To report bugs, please visit addon's homepage (https://mybrowseraddon.com/youtube-dark.html) and fill the bug report form.