User blog comment:Miskos3/Fairy Tail Episode 180: Garou Knights, Review/@comment-49.184.77.77-20140505055417/@comment-7418318-20140505142627

Maybe they forgot to colour it properly. It does have that typical shade of green that other forgotten places in anime had too and - except for Makarov jumping around - was a still-frame.

On the other hand, Bickslow is the only one of the Raijinshu who doesn't have a green Fairy Tail mark, so maybe that has something to do with it.