Tag Archives: TheDress

Press coverage of #TheDress

Whatever anyone thinks about the colour of dress and the attention it is received there is one undeniable fact – this story had received huge attention from the public and from the media. That in itself is probably more interesting than the debate itself.

The Daily Mirror story covered the angle that we are all right whatever we see because colour exists only in our heads. According to Dr Paul Knox, a reader from the University of Liverpool’s department of Eye and Vision Science, “Colour isn’t something that exists in the world. Different wavelengths of light exist and can be observed but colour is something we make up inside our heads.”

ITV also took the view that the explanation is that colour doesn’t exist. I broadly agree with this view, but the interesting thing is that that doesn’t explain why there was so much disagreement about the colour in this particular case whilst normally we barely notice any disagreement. If it is simply that colour doesn’t exist then why do we ever agree about colour at all?

On the other hand, in the Guardian an article by Bevil Conway considers cognitive processes in our colour vision and visual strategies that may vary from one person to the next. Of course, Bevil Conway is a super scientist and I agree with almost everything he says. Certainly, cognitive strategies could have something to do with this phenomenon. However, when he says that “By accident or design, the dress is a carefully created composition of orange and blue that confounds our visual systems,” I have to disagree. If you look at a properly taken photograph of the dress or the dress itself in real life what you see is shown below:

dress_original

The dress is not a carefully crafted composition of orange and blue – the dress is blue and black. However, Bevil is probably talking about the image that was circulated not the one shown above. To understand this phenomenon you need to understand colour imaging and the fact that colour images are sometimes not faithful reproductions. One of the reasons why this story has run and run is that there is no simple answer, no 10-second soundbite that can put the story to bed. It is a complicated phenomenon.

Extraordinary facts relating to the vision of colours

In 1794 John Dalton presented a lecture to the Manchester Literary and Philosophical Society about colour vision. The first two sentences are shown below:

It has been observed, that our ideas of colours, sounds, tastes, etc. excited by the same object may be very different in themselves, without our being aware of it; and that we may nevertheless converse intelligibly concerning such objects, as if we were certain the impressions made by them on our minds were exactly similar. All, indeed, that is required for this purpose, is, that the same object should uniformly make the same impression on each mind; and that objects that appear different to one should be equally so to others.

It is interesting to reread this sentence again in the light of the recent controversy about the blue and black dress.

Dalton

final word on the dress

Yesterday, I posted about The Dress that people see as either blue and black or white and gold. Following several radio and telephone interviews I wanted to have a final attempt to explain what is happening with the dress. It is quite an extraordinary phenomenon – yesterday the dress looked blue and black to me but my PhD student (looking at the same dress on the same screen) said it looked whitish and gold. When I came home last night and looked at the photo on my mac book, the same image that had looked decidedly blue and black to me before now looked whitish and gold. So what is happening?

The first thing is that it is nothing to do with the dress. The problem is with the photo of the dress. I believe that anyone looking at the dress in real life would certainly call it blue and black and also anyone looking at the manufacturer’s photo of the dress would also call it blue and black.

The second thing is that there is more than one phenomenon going on. The reasons why my PhD student and I saw different colours in my office may be a little different from the reasons why I saw it one colour on my pc in my office during the day and another colour during the evening on my mac. So, although people might like a simple answer and a soundbite, in my opinion the explanation is necessarily a little detailed. But I will try to avoid too much technical jargon below.

The camera does lie
I think many people believe that when they take a photograph and put in on the internet and people look at, what people are seeing is a faithful rendition of the original scene. People take this for granted, I believe, without giving it much thought. Unfortunately, this is not guaranteed. There are many reasons why the colour someone might look at in an image might not be the same one that was in the original scene. Different cameras capture colour in different ways depending upon the type of camera, the settings on the camera, and the light under which the image is taken, to name just three factors. In The Dress image, the image looks over-exposed and the colours are washed out. The black is quite pale and has a colour tint and the blue is very washed out and insipid. Hopefully you can see where this is going already.

Different displays show colour differently
You can put the same image on a PC, a mac, a smart phone and a tablet and look at it. The colours will probably not be identical. Reds will probably be red and blues will be blue. But the colours are likely to be not exactly the same on the different devices. If you are looking at your screen from an angle, the colours may change radically. Also, if you are looking at your screen in bright sunlight the colours may look more washed out – though some smart phones and tablets try to ‘intelligently’ correct for this which might make the problem better or worse. The fact that I saw the colours differently in my office than at home could be due to differences in the devices I was using or could be due to the lightening environment, The lighting in my office is quite different to that in my home, for example.

People see colour differently – a little bit
About 1 in 12 men are colour blind. Very few women are afflicted. But even for the rest of us – so-called normal observers – there is variability in our colour vision. One factor for this could be that there are known to be differences in our eyes from person to person. This effect could be small but may be a factor in this story. More important is probably the fact that if sit in a dark room for a while and get used to the dark our vision will be different to it would be if we were outside in bright sunshine. This so-called ‘adaption’ is one way our visual systems deal effectively with such a wide range of brightness from dark rooms to brightly illuminated outdoor scenes. Someone coming into a room from outside (where the sun and sky are very bright) might very well see different colours on the screen than some who had been in the room for a much longer period. These adaption factors are well known in science.

People don’t always agree on colour names
There are at least 3 million different colours in the world. How many colour names can you think of that we could broadly agree on? Words like, blue, black, red etc. There are others like beige and taupe where we might agree less well. But include these and how many do you have? 30? 50? 100? And these names have to cover 3 million colours!! So each name is a category that covers quite a large range of colours. Last year I published a paper where we gradually moved a colour from yellow to green and asked people to tell us when the colour went from yellow to green. Not surprisingly, the point at which people told us the name changed varied from person to person. So there are some colours that some people will call yellow and other people will call green. Correspondingly, just because two people are calling a colour by different names does not necessarily mean that they are seeing it as a different colour.

My final explanation
Variabilities in displays, viewing conditions, observers and colour-naming boundaries can cause disagreement in how to name colours. Normally, this would not shift a black to a gold or a blue to a white. However, in this case, the image that has caused the controversy is not a faithful reproduction of the original. Because of the way the image was taken the black has shifted considerably away from the centre of the category that we would call black. And likewise for the blue. In my office today I would still call it black. But it was not a strong convincing black. It was a little pale and had a bit of colour in it. To be honest, I could understand why someone else might call it gold. The colour was on the boundary between black and gold and now differences between people could cause it to be classified as one colour or the other. When I came home, the colours had shifted for me. I don’t think my colour naming boundaries had shifted. Rather, I think this was to do with the lighting I was viewing the colour in, or the screen (a mac rather than my pc) or the angle I was viewing my screen at. Any or all of these factors could have shifted the colour so that it passed from the category I call black to the one that I would call gold.

Maybe the surprising thing is that these controversies do not happen more. Colour imaging scientists have been phenomenally successful in delivering colour imaging devices that satisfy consumers. Part of this work is done at the University of Leeds where I work but there are other places around the world who make great contributions including RIT in Rochester USA. And then there are some super bright scientists in places like Samsung, Apple, HP and LG who have worked hard to understand the complexities of colour perception and colour communication to the extent that people barely even think about these issues. However, there is more work to be done. Colour is still a major factor in people being dissatisfied when they buy something over the internet. When the product arrives it is sometimes not the colour they expected it to be. And colour fidelity is still not good enough for many medical applications. If you want to get involved in colour science please contact me. My email is s.westland@leeds.ac.uk and you can also find me @stephenwestland

#TheDress

I was asked to comment on the radio today about a dress which is topping the trends of social media in the USA in particular today.

2622C22600000578-0-image-a-32_1425001827044

The dress has sparked controversy because different people say that it is different colours. There is a group who say it is blue and black and another group who say that it is white and gold. What do you think?

I will give my explanation but it is not simple so …

Now, about 1 in 12 of all men in the world are colour blind. But if we consider the rest of the population you may be surprised to know that there is variability in our colour vision. This is mainly due to the colour receptors in our eyes. Put simply, some people have more red receptors and some people have more green receptors, for example. So we know that we don’t all see colour in the same way.

There is a second complexity and that is just because we use different names for a colour doesn’t mean we see it differently. This most often happens with brownish colours where some people will refer to it as more of a green and others will be adamant that it is definitely a brown. So words – colour names in particular – are not always very precise. We can see at least 3 million colours in the world and how many names do we have? A few hundred at least.

There is a third complexity which is that people think the camera never lies – that is, that they take an image of something using their phone and put it on the internet and everyone is seeing a faithful reproduction of the thing they took a picture of. Sadly, the camera does lie. Variability in the light that is used to capture the image, the settings on your display (whether you have a warm white or a cool white, for example) and how bright the light is in the room when you look at your screen – these can all dramatically affect the colour. Take a look at the picture below:

dress_original

This is the manufacturer’s photo of the dress. Taken professionally, I think most people would see it as blue and black. But the image that is on the internet is very different. I suspect it was taken in a very bright light and the colours are consequently a bit washed out.

So, in summary, the camera does lie. I think the lighting conditions under which the photo was taken were far from ideal and have changed the colours from how they would have appeared if you had been there. However, that is only half the story. Since people looking at the same image on the same screen are disagreeing with the colours. To fully explain what is going on you need to invoke the knowledge that we can sometimes see colours differently (because of variability from one person to the next) and even if we see the colour the same we might give it a different name (because colour names are crude ways to communicate colour).

Of course, fundamental to this is the idea that things are not coloured at all but your brain constructs a colour from the signals it receives in the eye. This allows us, for example, to discount changes in colour that may occur when the light source changes (this is known as colour constancy). We have evolved to discount the effect of light being bluer or yellower, for example, so that we normally see the colours that the object would have in neutral daylight. In the case of the dress image it may be that people are using different processing strategies and discounting the effect of the light source in different ways.

Which all goes to show that colour is complex. But if you have been reading my blog you already know that, don’t you?