Anything is possible Jeff. One of the things that we know about Firefox, is its a pretty secure browser. Even Firefox's default settings make you more secure, and thats a good thing. I often get warned by Firefox when something is not quite right with a site.
Plus, there are a lot of great extensions for firefox that I enjoy. I recently came across one that I really love for Youtube, its like an enhancer of sorts. It lets me change settings that you couldn't on Youtube's page, I even changed the colors! lol
But thats why sometimes when I take a screenshot, if I am trying to see things how they actually are, I will have DARK MODE off, and look while logged out.