feat(YouTube): Monochrome thumbnails

[MaxVonMustermann]

Feature description

There are several browser plugins that not only replace YouTube-thumbnails, but make thumbnails (whether it is the originals or altered ones), completely monochrome. Maybe an additional button for filtering out colors from thumbnails is potentially possible.

Motivation

I hope this feature is not too hard to implement. It would help focussing more on decent content than focus on colorful clickbait. It helped me a lot to have this feature on my PC and other devices, only my phone does not support it, making doomscrolling more of a danger there. Therefore, I hope other people would benefit as well.

Acknowledgements

• [X] I have checked all open and closed feature requests and this is not a duplicate
• [X] I have chosen an appropriate title.
• [X] All requested information has been provided properly.