‘Confetti illusion’ makes fruit appear riper than it actually is

‘Confetti illusion’ makes fruit appear riper than it actually is

By Katharina Menne

Look closely at oranges in a mesh bag at the supermarket. They look ripe and delicious. But when you get home, you’re shocked: they’re still green! This is due to a perceptual phenomenon called chromatic assimilation or the confetti illusion, whereby objects appear to take on the color of the pattern placed on them. Products placed in mesh the color of ripe oranges sell better. This adds scientific evidence to what is already well known in the fruit and vegetable industry. (Of course, Citrus Red No. 2 dye can make green oranges look ripe, but uncolored fruits, such as organic ones, can be made to look better with the confetti illusion.)

Perceptual psychologist Karl Gegenfurtner at the Justus-Liebig-University Giessen (AS1) in Germany has shown how this illusion works for fruit in a short paper published in the journal Nature. i-PerceptionPerceptual illusions are generally understood to be incorrect interpretations of sensory stimuli. This phenomenon is based on the fact that stimuli always represent incomplete information, which can only be combined with experience to produce a sensory impression. This can lead to errors.

Gegenfurtner himself had previously noticed that the oranges he had bought were not as ripe as they looked through the net. Though initially disappointing, the colour researcher’s interest was piqued. To rule out the possibility that the observed effect was caused solely by reflections between the net and the fruit, he made a graphical reproduction of the net as stripes and placed a photograph of an unripe orange, with a greenish shimmer, behind it. Lo and behold, the fruit suddenly appeared noticeably darker.

Supporting science journalism

If you enjoyed this article, please support our award-winning journalism. Subscribe. By purchasing a subscription, you help ensure a future of influential stories about the discoveries and ideas shaping the world today.

“These findings highlight important implications of color assimilation in everyday consumer environments and offer a new perspective on how vision is manipulated,” Gegenfurtner wrote in the study. “Looking around a typical supermarket, it is easy to see that fruits and vegetables (such as lemons, onions, zucchinis, and even potatoes) are wrapped in nets of the same color as the typically perfect specimens.” Light reflections between the net and the fruit may also increase the saturation of the colors.

In his paper, to show how powerful the optical phenomenon is, Gegenfurtner demonstrated the confetti illusion on the faces of Hermann von Helmholtz, James Clerk Maxwell and Thomas Young, the founders of the three-color theory. The effect is astonishing: the faces change color depending on the color of the stripes. And in a black-and-white version of the demonstration, the faces become very dark or very light. The illusion provides “good laughs for color scientists and sad moments for consumers,” Gegenfurtner concluded.

This article was originally published on The scientific spectrum Reprinted with permission.