Color Perception: An Impressive Illusion

"Awesome Illusion"
Mr. Science Show (June 25 2009)

"This illusion has been doing the rounds this week (see Bad Astronomy and Richard Wiseman for a couple of science blogs I like that picked it up), but it's so good I thought it needed to be posted here also.

"Look carefully at the image below. Do you see a couple of spirals, one blue and one green? Well, take a closer look - in actual fact, the blue and green are actually the same colour!..."

The post shows a larger version of that thumbnail, and two enlarged segments from the graphic. It also briefly tells why the 'blue' and 'green' appear to be different colors. And, yes: they are the same color.