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Optical illusion

Colour contrast

How many shades of green and red can you see?

This image is in colour and it is made up entirely of dots. Two diagonal lines of dots cross the rectangular background, comprising light green and white dots. Neither line is straight and both vary in width along their lengths. The line running from top left to bottom right is made up of red dots, but the line running from bottom left to top right contains two sets of coloured dots – in the centre the dots are red and around them are green dots which are effectively more densely packed as, unlike elsewhere in the green rectangle, there are no white spaces between the dots. The effect of placing green next to red makes it look much darker than green next to white. So although this picture is, in fact made up of dots of only one shade of red and one of green, it looks as though there are four colours present - pink, red, light green and dark green.

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Answer

Did you know?

Eating brocoli, spinach and other similar vegetables regularly can help prevent eye disease. Find out more