To create an optical illusion image is not as easy as you thing.
This is one of the most amazing optical illusion tricks, this trick deceived your mind to color an black and white image after concentrate on a saturated colored image for a while. Just look at the dot in the middle of this image and don't look anywhere except the dot in the image, after moments a black and white image will appear but you'll not see it black and white, you will see it colored.
How our brain translates the first image to combine the colors and to arrange it to see colored black and white image.
Physiological illusions, such as the afterimages following bright lights, or adapting stimuli of excessively longer alternating patterns (contingent perceptual aftereffect), are presumed to be the effects on the eyes or brain of excessive stimulation or interaction with contextual or competing stimuli of a specific type—brightness, colour, position, tile, size, movement, etc.
An optical illusion is characterized by visually perceived images that differ from objective reality. The information gathered by the eye is processed in the brain to give a perception that does not tally with a physical measurement of the stimulus source. There are three main types: literal optical illusions that create images that are different from the objects that make them, physiological ones that are the effects on the eyes and brain of excessive stimulation of a specific type (brightness, colour, size, position, tilt, movement), and cognitive illusions, the result of unconscious inferences.