Health & Wellness

The dress is blue. Here's why

OK, that dress really is blue and black but it sure doesn’t look that way to a lot of people.

@switek via Tumblr

The tongue-in-cheek debate about the color of a dress offered for sale on a British website is breaking the internet, but it’s delighting neuroscientists who are getting a chance to explain why vision is so weird.

In this case, it’s probably because the image is overexposed, experts said.

“Based on what I have been able to gather from the internet, the image is of a blue/black dress that has been significantly overexposed resulting in its general white/gold impression,” says Mark Fairchild, director of the Program of Color Science at the Rochester Institute of Technology.

“The blue and black are reflecting enough light to scale up to white and gold with the overexposure. What little you can see of the background shows this overexposure (and that overexposure has been digitally enhanced in some versions floating around the internet).”

His colleague Roy Berns agrees.

“A lot of time in an overexposed image, colors can clip,” Berns said. “It’s kind of re-defining what white is for you. If it had been a photograph taken a little further back and not overexposed, it would have shown…blue or black.”

That’s because the eye doesn’t just see true and pure color. It’s all interpreted in the brain. You brain is busy calculating what the ambient light is, whether an object is in bright light or in shadow. And it can be tricked by the surrounding colors.

PHAS / UIG via Getty Images

Dr. Lisa Lystad, a neuro-opthalmologist at Cleveland Clinic’s Cole Eye Institute, says the background is a big factor.

“On the right side the background is very white and yellow whereas on the left side, the background to me looks much darker and much more black and white,” she said.

“If I look at the brighter part, which is on the right side, and cover up the other side, it looks like a lighter color.”

By the way, Lystad sees the dress as a gray-blue color with gold stripes.

There’s more to it than that, says Fairchild.

“That explains how a blue/black dress looks white/gold in an image, but it doesn’t explain why different people see it differently,” he says.

Part of it is that it’s a small image on a computer screen, which can change as your point of view moves, or with the brightness and color settings on the computer.

“However, this is only a partial explanation and does not explain how two people viewing the same display might see the dress differently [which apparently does happen],” he added.

“The second, and more important explanation, in this case, is through a perceptual mechanism we call ‘discounting the illuminant’. Humans perceive object colors based on the light coming from the object and their understanding of the illumination falling on the object. If we are tricked somehow and make the wrong interpretation of illumination then we perceive the colors of objects incorrectly.”

So if you perceive the lighting to be light and bright, you’ll see a blue dress. If you perceive the illumination to be dim, with the dress in shadow, you’ll see a white/gold dress.

And a third factor is that it is a photograph and not a real dress.

“If we were in that physical space we would know what the lighting is on that particular dress. We are not getting a true sense of what the lighting is,” said Berns, whose graduates tend to go and work for companies such as Apple, helping to design better cameras.

“Whoever took this picture is not a fashion photographer.”

Berns also agrees the dress is blue.

“In the case of the offending dress, I read that Taylor Swift thinks it’s blue and black and that’s good enough for me,” he said.

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