From bug 70576 comment 4 by Isarra:
I still don't like that border. #aaa is awfully dark when it's just white
all around on both sides, especially in skins like vector with a lot of much
more subtle colour transitions. The appearance in others could be
subsequently HORRIBLE but that doesn't really apply to wikimedia.
Is there really no generic core class for this kind of thing where you can
just apply to the new stuff like this? Be something toc, editoptions,
categories, and anything else along those lines would also use, such that
they all automatically match regardless of skin, or origin? Seems like that
would be neater.