Board Thread:Support Requests - Getting Technical/@comment-4723271-20160624184343/@comment-24055022-20160624185501

That is not a standard infobox, it's a portable one. I believe this code will help:

.portable-infobox .pi-border-color { border-color: (color); }

You add it to your MediaWiki:Wikia.css, change (color) to whatever color you would like. I hope that helps!