This is one of the dumbest discussions of color in recent memory. I saw a number of sites showing the dress differently AND the bkgnd elements too, indicating not only is this a color management nightmare of image posting of untagged data, the RGB data is all over the map too. Optical Illusions as the Nightly News suggested? A group of awful, different, un-color managed images?
If any good comes of this silliness, maybe the masses who never considered that what they see from images on the internet can be horribly mangled will open their eyes to how unreliable the web is for posting awful images that are awfully produced can appear.