Board Thread:Support Requests - Getting Technical/@comment-35301431-20130210074345/@comment-10688548-20130210075505

If you place this in your Special:Mypage/wikia.css on the wiki in question, not here I think it should override the local background. If you're feeling adventurous, you can modify the code (change the background-color to another color name) and use that.

Or, perhaps try voicing your concerns to the wiki's admins.