Often I want "a bit darker" just to take the edge off blinding white light. This HN page for example, I use the Stylus browser extension to reduce the backgroun

Often I want "a bit darker" just to take the edge off blinding white light. This HN page for example, I use the Stylus browser extension to reduce the background white of page and this text box to a medium grey. Same for Wikipedia. I tried making a Stylus entry that worked on any website, but couldn't do it.