Sorry, this is not Windows per se.
Today, at some point, YouTube videos suddenly started appearing with a cream-colored tint instead of white. It’s not my nighttime Windows nightlight; I checked. My Dell 8920 XPS, according to Support Assist, needs no driver updates. In searching for an answer, I saw one mention saying that all HDR videos require this and to disable or enable hardware acceleration in Windows settings, but I’m leery of this. Eeeryhing else looks fine on my monitor; in fact, in B&W videos, even the thumbnails that pop up when hovering over the video time line are untinted B&W, even though the full image is tinted (see attachment).
Any idea what going on?