Board Thread:Support Requests - Getting Technical/@comment-1295676-20160902212709/@comment-5454372-20160903013344

I think that's actually a portable infobox you're using, so there're some things I don't entirely understand about it (namely, how using a  inside the image field of the infobox is somehow generating the tabs -- I haven't seen galleries do that prior to portable infoboxes being used).

From the looks of things though, I think the background colour you saw was actually its default behaviour: slideshow galleries like the one below also take on a background colour, and when used on your wiki, it seems to be the same colour as the tab background you saw earlier in your infobox.

Basically, I think what you originally saw was pretty much what it was supposed to do according to Wikia (i.e. part of the mass colour settings Wikia does by default when you use Special:ThemeDesigner to broadly specify your colour themes). There weren't really any "problems" with it, it was just finding the exact CSS selector to pick out and override the behaviour you didn't want.