Color Illusions are images where surrounding colors trick the human eye into incorrect interpretation of color.
You may want to hide some parts of the optical illusions by your hand so that you don't get distracted by the rest. You may even use some online color picker tools to verify that the colors are identical.
Don't let your eyes trick you :-)
Color Blind Test
Let's start with a simple color blind test. Unless you are color blind, you should see 58 (upper left), 18 (upper right), E (lower left) and 17 (lower right).
Dress Color Illusion
Is this dress "white and gold" or "blue and black"? Millions of people voted at buzzfeed.com and around 70% see the dress as white and gold. So are the remaining 30% wrong?
Nope. Actually, what you might see as white is actually blue. Cover everything else and look at just a small part without any surrounding colors. You'll see it's blue. (posted originally by swiked on tumblr)
Same Color Illusion
Also known as Adelson's checker shadow illusion (published by Edward H. Adelson) depicts something hard to believe. Square marked B looks considerably lighter than square A, due to the "shadow" being cast upon it. However, color on both squares is precisely the same shade of grey. If you don't believe, use any eyedropper tool or print/cut the squares to verify that both square A and square B are precisely the same.
All grey rectangles are of equal luminance, although the ones in the dark stripes appear brighter than the ones in the bright stripes. (by M. White)
Believe it or not, but the pieces A/B/C all have the same color. Use any color picker, graphic program or simply cover the remainder with your hand to see for yourself.
Surface color of both A and B parts is identical. Just use a finger to cover the place where both parts meet and you'll see.
Yellow Dog vs Blue Dog - both of them have the same color.
The upper chess set is black and the bottom set is black, right? Wrong. Both sets have absolutely the same color, just the background changed. (by Barton L. Anderson and Jonathan Winawer)
Red vs Green
When you first look at this, how many colors do you see? Some might say they see 3 or even 4 colors, but there are 2 - red and green! People usually think they see 2 shades of red, but there is only 1. Look closely and you will notice on one side that white boxes surround the red boxes, and on the other side, green boxes do! Due to the placement of these boxes you get the "illusion" of different colors. Since white is not considered to be a color (it is the presence of all colors in scientific terms) we can safely say that there are 2 colors present here! Still don't understand?
Grey vs Blue Stripes
Focus on the black dot in the bottom right hand corner and the moving grey stripe will eventually turn blue.
Also known as Pac-Man illusion is another example of afterimage complementary color (green as opposite to lilac). Follow the movement of the rotating pink dot with your eyes and the dots will remain only one color, pink. But if you stare at the black + in the center, the moving dot will turn green. (by Jeremy L. Hinton)
If you like these brain teasers then feel free to share them with your friends.