How many shades of green can you see in this effective illusion?
The two shades are actually just one, but because of the placement in the illusion they appear as two different shades. There is a perspective illusion at work too; the darker green shade appears closer to the eye than the paler green because of the way it is placed on the beige strips, whereas the paler green is retreating into the background, behind the beige strips. However, there are only three colours at work in this illusion, not the 4 that our brain tells us we are seeing.
Shades of green
Looks like 2 different shades of green, right?
But there's only ONE shade of green.
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