User style for fixed font, white text and black background.

white-on-black.css

@-moz-document url-prefix(http://), url-prefix(https://),
               url-prefix(about:sessionrestore), url-prefix(about:newtab) {
	* {
		color: white !important;
		background: black !important;
		font-family: Fixed, monospace !important;
	}

	body {
		font-size: 18px !important;
	}

	a { color: #A0A0FF !important; }
	a * { color: inherit !important; }
	a:visited { color: #00DD00 !important; }
	
	tt, code, pre {
		font-family: monospace !important;
		font-size: 0.8em;
	}
}