I know about that, and I use it whenever possible. However, some sites (for example Mastodon) is a dynamic web application. There is a plugin I used to use, ca

I know about that, and I use it whenever possible. However, some sites (for example Mastodon) is a dynamic web application. There is a plugin I used to use, called "care for my eyes" that allowed me to change the colours. However, its main purpose is to swap colours for people who prefer black background (a bit strange to me, but I accept their opinion) but it used to have an option to do the opposite. Unfortunately, that option is now gone so I am again unable to use sites with black background.