Ridiculous optical illusion

I just saw an optical illusion that was hard to believe was an illusion. The "blue" and "green" in the spiral below are actually the same color. REALLY.



What's even more amazing about this illusion is that it fools software too. The color blindness software I posted about yesterday translates this illusion into the colors we perceive, not the colors that are actually there. In fact, so does image compression software. This "bug" might reveal something interesting about how human sight actually works.

Double Wow.