This is a demonstration of a spatial phenomenon, caused by the fact that we have relatively few S cones in our retina.  In turn, this means that S cones alias signals that have high spatial frequency.  The most obvious signs of this are that narrow blue stripes look green (and blue text is notoriously hard to read).  Look at the sets of stripes in the next three slides --- do the narrow ones look greener?

Here’s a chance to see them all together; again, narrower ones should look greener.  You can also demonstrate adaptation with this slide.

Tente ler as cores da coluna da esquerda, da direita e do centro (nesta ordem) o mais rápido possivel.