I tried it with a local file with a black background which turned white. It seems my dark theme is not handled well. The local page works well normally. I removed the addon for now.

It flashbangs - when opening new tab there's a flashbang of white, then switch to black. For me this defeats the whole purpose of this addon.

thank you

Very useful to override the Home Page overrides imposed by my Company.
This is exactly what I was looking for :-)