How many colours do you see in this image?
The blue and green spirals are actually the same colour — green. There is no blue colour in this image.
The brown and ’orange’ squares in the centre of the top-facing sides of these two cubes are actually the same colour.
Look carefully at the chessboard. What colour are the squares “A“ and ”B“? Does “A” seem black and ”B” seem white to you? Find out whether you’re right or not below.
© E.H. Adelson
Both the “A“ and ”B” squares are the same colour! Grey.
The bottom part of the figure seems lighter, doesn’t it? Now hide the horizontal line between the top and the bottom parts of the figure with your finger.
Do you see a chessboard with black and white squares? The grey halves of both black and white squares are actually the same colour. The colour grey can be perceived as black or white depending on the colour next to it.
The horse figures in this one are the same colour too.
How many shades of colour are there here, excluding white? Three? Four? In truth, there are just two — pink and green.
And what colour are these squares? Either green or pink — nothing else.
When your eyes play tricks on you
No matter how hard you try you can’t focus on either of the images.
Look at the dot, and the grey stripe on the orange background turns into…a blue one.
Click on the image. A green blot, moving in circles, replaces the disappearing violet spots. However, it doesn’t exist in reality! Moreover, if you concentrate your attention on the cross, the violet spots will disappear altogether.
Click on the image. Look at the black dot in the centre for 15 seconds. The image will become colourful.
Look at the four dots in the center of the image for 30 seconds. Then look at the ceiling and blink a few times. What do you see?
There are black spots at the intersections of all the white lines — except for the one you are looking at right now. In reality, these spots don’t exist.
If you look closely at the dot in the centre of this image for a few seconds, the grey background will vanish.
Focus on the centre of the image. After a few moments, the blurred, colourful shapes will disappear, rendering the background completely white.