Staycalmsyndrome If it's a recent update, you could try to disable "auto-update apps" in Google Play Store and downgrade the Youtube app.
This does not work. The Youtube app is just a wrapper. It displays whatever the current YouTube UI is.
There's this browser extension Stylebot which allows you to change any HTML element to your liking visually,
This is on Android TV, not in a browser. I already use Stylus extensively
Allekss It's like more depth in colors and that gives me eyestrain !!!
Yes, they made the darks darker and the whites brighter
I managed to get the source code for SmartTubeNext downloaded, set up the project in Android Studio, and compile and deploy it to my FireStick. I'm not an Android developer, but I have figured out how to modify the color scheme to be like it was before, so color wise that is fixed. Videos play fine, but the UI is locked at 60fps and I need to knock it down to 30 to be better for my eyes. I am working of figuring out how to do that.
If any Android devs out there want to help, let me know