Thread:Extension talk:Header Tabs/how can I change the color of the tabs?/reply (2)

The core of the jqueryUI tabs styling is located at $IP/resources/jquery.ui/themes/vector/jquery.ui.theme.css underneath the Interaction States 'header.'

Keep in mind this folder will by default be written over upon mediawiki software update, so back up any confs you changed in there beforehand.