The colored areas seem to be surrounded by the "Aura" of a different color. When peripheral sensors are stimulated for some time, we have color sensations, which are much different than when we use our central vision.

The longer that we concentrate, the brighter is the 'Aura' around the colored areas, because our sensitivity increases. Yesterday, we could look at this picture for hours and never see anything. Concentration at one spot for long enough is the key.

Rather than the true Aura, this exercise demonstrates the principle of how to look, to see human Auras by making us aware of certain specific capabilities of our eyesight, and our perception.