User blog comment:DiegoAnime3000/Black is for Polarity/@comment-15145664-20140110234404/@comment-15108745-20140111031506

But then if Black represents gravity and a control of push/pull forces on objects, I guess the next question would be how that relates to Pyrrha's hand glowing black. That is, if her hand glowing has anything in common with Weiss' glyphs' colors, and we assume that Black represents push/pull forces, then why isn't Pyrrha able to push or pull any object? If her semblance is polarity then she should only be able to move metal objects, which is all we've seen her do so far.