Opponent colours induced by rotating discs

We found a novel visual illusion by using a rotating disc that has some coloured sectors with black arcs. When this disc rotates, illusory colours are seen in the concentric rings that are created by the rotating arcs. The illusory colours are the opponent colours of the sectors that the corresponding arcs are in. Even though we could not differentiate the colours of the individual sectors when the disc rotated quickly, the illusory colours that were the opponent colours of the sector colours could be seen. This visual illusion thus suggests that our visual system can process visual stimuli that we cannot perceive as colours.