i’m searching for a software that allowed me to set up firefox….. so that all website that i browse only remain with my own custom css background….
Reason for me doing that~ well some websites i browse have a very light css BG(white) ~ i want to make them all black(dark) images to fit with my current theme

go to the tools menu, then go to the content tab. on that tab uunder fonts and colors is a button for colors. in the next pop-up choose the colors you want then un check the “allow pages to use their own colors blah blah blah.