YELLOW BLUE ORANGE BLACK RED GREEN
PURPLE YELLOW RED ORANGE GREEN ORANGE BLACK BLUE RED PURPLE GREEN BLUE
Look at the words above from left to right, read out the color, but not the words. For example, the first word you say should be green (the color of the word.)
Difficult, isn’t it?
This is caused by left-right brain conflict. The brain is divided into 2 sides. They control different modes of thinking. The right side of the brain is more intuitive, holistic, and synthesizing so it is more responsible for perceiving, colors, graphics, etc.
The left side of the brain is more logical, sequential, and analitical. It is more responsible for perceiving words and meanings. When you are reading the words, the right side of the brain tries to say the color, however, your left side of the brain insists on reading the words. This conflict causes the confusion in perception.
From Illusion Science.