monochrome

Optical illusions, like this one from artist and software engineer Øyvind Kolås (note no gratuitous metal umlauts here) that illustrates the brain’s facility for colour assimilation (also called the von Bezold spreading effect for the Münchener meteorologist who first described it), have always engaged and captivated (see also) us because of their sheer pernacity in showing us how easily we’re fooled in a form that’s not so simply rebuffed or dismissed, like saying we’d never fall for this hoax or be a victim of that scam.  There’s no disenchantment in the explanation in a video at the link up top either, and maybe if you look hard enough you will see it’s a black-and-white photograph of a classroom overlaid by those chromatic grids.