User blog comment:Rupert Giles/Introducing Updated Global Navigation/@comment-5557418-20141008021839/@comment-24325645-20141008115021

Well, according to a wikia message from my email it says:

"Thanks for contacting Wikia. The global navigation is something that will be added to all Wikia communities without an opt-out feature, and we are not allowing custom CSS on it. Unlike most parts of a page, the global navigation is Wikia-owned space that we create and design for navigating around a community, navigating around Wikia, and for Wikia branding purposes. Advance customizations on a community should take into account that, sometimes, designs change."