what colour is this

suppose you guys already seen this, however forwarding in case any one not seen..
http://www.iflscience.com/sites/www.iflscience.com/files/styles/ifls_large/public/blog/%5Bnid%5D/gcmrcydrfpdfyamqbp8w.jpg?itok=RziySpNv

"What colour is that dress?" The question has been fascinating people all around the world, including Prof Barry C Smith of the University of London's Institute of Philosophy.
We all assume that we see what's before our eyes, and if we have normal colour vision we should be able to tell what colour the dress is. And yet we've just discovered that the world of observers divides into two groups - those who see the dress as white and gold, and those who see it as blue and black, or blue and olive green. They know they are looking at the same image and that it isn't changing, so why is there such marked disagreement about how the dress looks?
Could it be that we all see the world very differently? Have we just discovered that there is no such thing as the true colour of things? Is colour just in the eye of the beholder? That may be a tempting conclusion, but the philosopher Ludwig Wittgenstein would have resisted it. He was famous for pointing out errors in our everyday thinking. So when told by his pupil, Elizabeth Anscombe, that it was easy to understand why people thought the sun went round the earth, Wittgenstein asked, "Why would they think that?" "Well," said Anscombe, "it looks that way." To which Wittgenstein replied, "And how would it look if the earth went round the sun?" The answer, of course, would be: "Just the same."
So how might Wittgenstein have reacted to our query about the true colour of the dress - or to the fact that people who up until now have agreed about the colours of all sorts of things suddenly see the dress so differently? After all, the same wavelengths of light are entering the retinas of each observer. How can it look white and gold to some and blue and black or olive green to others?
Wittgenstein might have pointed us to Marcus Jastrow's duck-rabbit figure.
When you look at the drawing, without it changing, it is possible to see it either as a duck or a rabbit. You can't see both animals at once but you switch from one to the other. Wittgenstein called this "aspect-switching" since you see one aspect when you notice the long shapes as rabbit's ears, and another when you see them as a duck's bill. The same object can look completely different when we attend to parts of the drawing and think of them as a duck's bill or as a rabbit's ears.
So is it the same with the dress? There are good reasons to doubt it. Not many people report being able to switch between the blue-black/olive and the white-gold colours. Instead, it is looking at the image on different monitors, or in different lighting conditions that induces a change.
And there's the clue. Just as in the case of the duck-rabbit figure, it's not just what we see but how we think about what we see that influences how something looks; and most people who see the dress as white and gold say the white colour of the dress is being tinted by a blue-ish light. In fact, what they claim to see is how a white dress looks in slightly blue lighting.
For the rest of us - whose visual systems don't wash out the blue when it is illuminated by blue lighting - we don't think of it as parts of a white dress reflecting blue light but as a parts of a blue dress in white light. Between what we all see and how we judge what we see comes the thought, and thoughts make us look at the same things differently.
In the case of the dress, both ways of viewing the colour in the image are illusory but unlike Wittgenstein's cases of aspect-switching, it's not a shift of attention or a difference in background ideology that separates the two ways of viewing the dress. It's a categorical difference in the ways our visual systems interpret colours in the world - a difference we have only just discovered.
Wittgenstein had thought of using a sentence from Shakespeare's King Lear, "I'll teach you differences" as a motto for his Philosophical Investigations. This would be a perfect example.

BBC News.

To me its Black and Blue.

The first time I saw this picture on another site, I saw it as white and gold, then again on another site as white and gold. Now I see as black and blue here and elsewhere.

(CNN)Before you strangle your best friend who sees the colors in the now-famous dress differently than you do, please know that there's a scientific explanation.

It has to do with the tiny cones in the back of our eyeballs that perceive colors in a slightly different way depending upon our genes.

"Why do some people love cilantro and others say it tastes like soap? Why do some people have perfect pitch and others are tone deaf? It's the same with vision — our sensory apparatus is fine tuned," says Dr. Julia Haller, the ophthalmologist-in-chief at Wills Eye Hospital in Philadelphia.

The cones in our retinas — the fine layer of nerve tissue that lines the back of our eyes — detect the blue, green, and red in an image. The cones and your brain mix those colors to make other colors


"Ninety-nine percent of the time, we'll see the same colors," Haller says. "But the picture of this dress seems to have tints that hit the sweet spot that's confusing to a lot of people."

The very top section of the dress appears gold to some people, but black to others.

This makes sense to Haller.

"One of the typical color confusions we see is blue/yellow," she says. "So perhaps in this dress, the black has a bit of blue and the gold has a bit of yellow."

As retinal specialists met Friday in Scottsdale, Arizona, at the annual meeting of the Macula Society, they swapped theories about why people's cones and brains process the dress's colors so differently.

One theory has to do with evolutionary biology. Primates, including humans, have developed an excellent sense of color, so we're able to, for example, distinguish the yellow fruit hanging on the green tree.

To determine the color of that fruit, it's often necessary to factor out colors in the light around it that might give the fruit a different and misleading tint. There are likely slight variations in how our brains do this automatic filtering.

"Your brain is constantly estimating the color of the light that's falling on the object and factoring that light out," said Wallace Thoreson, a professor of ophthalmology at the University of Nebraska Medical Center. "Each of us makes slightly different unconscious assumptions."

Opinion: Why the dress, llamas and Spock went viral

Haller said the Macula Society's meeting was "totally derailed by the dress" as doctors skipped sessions to stand out in the hallway and compare each other's color judgments.

Some of them even think the dress could possibly help advance medical science and hopefully help people with vision problems.

Dr. Emily Chew, an ophthalmologist at the National Institutes of Health, said in more than thirty years of research she's never seen an image where people, all with normal vision, have had such dramatically different responses.

"It would be interesting to use this image to learn more about the pathways of how we understand color," said Chew, the deputy director of the division of epidemiology and clinical applications at the National Eye Institute.

She said it was impressive how "crowd sourcing" identified the dress.

"It would be really hard to create this image," she said. "It's serendipitous. I've never seen anything like this. It's really unbelievable."

chinwi wrote:To me its Black and Blue.

to me that looks like a flat ass!

jiggysaurus wrote:

chinwi wrote:To me its Black and Blue.

to me that looks like a flat ass!