Firefox CSS to change the accent color on top of tabs. Use with userChrome.css

custom-accent.css

/*
1. Navigate to `%APPDATA%\Mozilla\Firefox\Profiles ...` or locate the exact directory at `about:profiles`
2. Create a folder named `chrome` then create a file named userChrome.css inside it and paste this code
3. If userChrome.css doesn’t seem to work, open `about:config` and set `toolkit.legacyUserProfileCustomizations.stylesheets=true`
*/

@namespace url(http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul);

.tab-line[selected="true"] {
	background-color : #841ebe;
}

#urlbar[focused=true] {
	border-color: #841ebe !important;
}