YouTube Only Video for Chrome
More About YouTube Only Video
Sometimes you just want to remove every HTML element from the YouTube page and be alone with the video you're watching. Indeed, it happens a lot.
The extension is activated when its icon is clicked from a tab where a YouTube video is being played. Once clicked, full screen mode is activated and the current window will only show the YouTube video's frame; a pop-up that contains a color palette will appear too (second screenshot). This provides different ways to select the color for the page's background. Also, It can activate a mode where the color will be set to the video's current predominant one dynamically. These functions are shown in the linked video: https://www.youtube.com/watch?v=gUc8nfeJWoU.
This extension doesn't emulate an Ambilight technology. If you're looking for something like this, I recommend you the following extension, that provides really professional and pretty results: YouTube Ambilight, by Wezelkrozum (https://chrome.google.com/webstore/detail/youtube-ambilight/paponcgjfojgemddooebbgniglhkajkj).
FYI: Extensions are not activated automatically when they are installed. This extension, like many others you have tried probably, starts working on all the corresponding tabs at the right moment it is installed, but this is not the default behaviour. Take in mind that if you install an extension sometime and it doesn't work on the tabs you have already open, you may need to refresh those tabs with F5 key or by clicking on the reload button located in the browser's top left corner.
These tools make the extension work:
—jBox, https://stephanwagner.me/jBox/demo/draggable-popup-windows (https://github.com/StephanWagner/jBox)
—Spectrum, https://seballot.github.io/spectrum (https://github.com/seballot/spectrum)
—Color Thief, https://lokeshdhakar.com/projects/color-thief (https://github.com/lokesh/color-thief)