User blog comment:DaNASCAT/Technical Update: September 27, 2011/@comment-1401334-20110928155354

Apparently Wikia decided to change the class names on the page backgrounds and didn't think this was important information to share pre-release. As a result, the wiki where I am administrator had white background behind white text for half a day before I logged on and noticed.

Information about that kind of big change should be put in the technical updates, because it is very important to wikis that have customized their skins.