Some Visual Trickery

Do the squares A and B have the same color?
I usually try to aim for puzzles that have something to do with physics or math on this blog, but this is so incredulous that I had to include it.
Take a look at the image. Would you believe that squares A and B have the same color? (not the letters A & B, the squares themselves.) Yep, there goes your mind again, playing visual tricks on you. But it’s true! If you don’t believe me, take the image, put it in your favorite image editor, cut out patches from each square and put them next to each other.
The really annoying thing about this is that, even after you’ve learned they have the color, you still can’t see it! Your mind tries to make reality fit into a predefined notion that just isn’t true. Makes you wonder about eyesight testimonies given in court, or other ways in which we trust our vision a bit too much.
ADDED 27-MARCH-2009: to make the illusion a bit more clear, I’ve cut out squares A and B and put them next to each other. I’ve also juxtaposed the letters A & B on the same square, making it clear they’re not the same (I’ve done it using Paint, but it really can be done with any simple drawing program):


I tried it, but I must have done it wrong. For me it’s a distinctly different color… what the heck?
Nick,
I’ve downsized the image a bit so that might be the source of the change in colors. I’ll look into it and report when I get a chance.
Wow, that’s cool…
I tried it in Paint… The colour’s RBG 107 each!
If u erase everything other than the two boxes, only then can u see that the colours are the same… The Mind and it’s tricks…
One of my favorite optical illusions
An easy way to see they’re the same color without using an image editor is covering the image with both hands, leaving only the A and B squares in sight. You will immediately see they are indeed the same color!
A cool illusion, indeed, but hardly “incredulous.” Perhaps you meant “incredible.”
Thank you.
‘Incredulous’ has been used to mean ‘incredible’ in quite a few sources - including Shakespeare. But I suppose it might be a confusing choice of word because of its ambiguity.
If you put your eyes out of focus and stare between the two squares in question, it becomes clear that they’re the same shade of gray. At least, it works for me.
questions
does this not imply the two letters a and b that id the two squares are the same color as well?
but if the letters are moved one square in any direction would they not blend into the new square’s background?
then doesnt this mean that both letters are different colors?
and therefore both original squares are different colors too?
does my logic hold?