I tried to do it through the web developer tools option, but I had no idea what I was doing…I’m trying to change the dark blue theme to a dark black background w/ white text because my vision, especially my color blindness, gets worse when I’m exposed to dark blue themes…Does anyone know how to do this? Thank you.
Firefox does not have built in support for modifying site themes. While you can use the developer tools to modify a site’s styles, changes you make will be lost when you refresh the site.
That said, there are a few extensions out there that provide this functionality. I’m not endorsing either of these, but I believe Stylus and Stylish are two such options.