Turn on YouTube Secret Dark Theme the Easy Way
In most cases, YouTube’s white background is fine. However, when you sit in a dark room and watch a video, against this white background, it can appear that you are looking at the sun (which, as we all know, is impossible due to the approaching eclipse). If you often watch YouTube late at night, there is actually a hidden dark mode you can turn on that converts all that white to black, giving your eyes a much-needed rest and transforming your YouTube viewing experience into something more like a movie.
We actually wrote about this feature a few months ago , but it took a lot more work (and some crazy code insertion) to make it happen.
To try this feature now, first go to youtube.com/new and register. The dark theme is part of the new experience the site is currently testing. While it will likely be available to everyone eventually, you must agree to participate in the preview right now to try it out. Other features include a redesigned home page.
Once you have turned it on, you can activate Dark Mode by clicking your photo in the top right corner and choosing “Dark Theme” from the drop-down menu. You can turn this feature off and on from here so you can watch with any background color you want.