Lying brain

Lies, lies, lies! I'll never trust my brain again. Lying bastard brain.  My eyes dutifully report, and my lying brain lies, lies, LIES! Believe it or not, and I didn't so I tested, the green and blue spirals are the exact same color!

Apparently our brains interpret color by comparing them with their surroundings.  The trick of this illusion is the orange lines cut through the green spirals but not through the blue spirals.  It looks as if the orange lines cut through the blue spirals but they do not, those are pink lines cutting through blue, and this forces our brains to reinterpret both colors. 

I used color picker in both Photoshop and Image Ready then used bucket tool to dump the color onto separate areas on separate layers, just to be careful there would be no unseen automatic mixing of colors within the programs, then chose those colors again from the fields to read their HTML code names.