People are going insane debating the colour of this shoe

People are going insane debating the colour of this shoe

Remember the greatest controversy of 2015? Nope, it had nothing to do with North Korea or anything the president of the United States said, but the argument over what colour a certain dress was. Known as "the dress", the photo went viral in February 2015, as some viewers saw it was black and blue while others saw it as white and gold. Ah, what a simple time that was.

In the first week of the image being online, more than 10 million tweets mentioned the dress. Eventually it was revealed to actually be black and blue (I knew it!), but the discussion still raged on for some time. But if you thought we'd left these conversations behind, you would be way off the mark.

Now there's a new item to bring up this bewildering debate once more, but this time it's not clothing, but footwear. Across social media, people are asking the question: is this shoe turquoise and grey, or pink and white?

As you can imagine, this kind of thing drove people crazy. First thing I saw was a shoe with grey material and turquoise laces (or green mint), and when I learned that people were seeing it as a pink shoe with white laces, I looked closer. The weird thing to me is that after looking at it for longer, many people actually switch to pink from grey, but I just couldn't see anything else, no matter how hard I tried.

With over 24,000 people retweeting (choosing pink and white) the post and 137,000 people liking it (grey and turquoise), the public made their decision known. Originally impartial in his question, the person who originally posted the above tweet made his answer clear:

While others disagreed...

But it all becomes more complicated when some users tracked down the actual shoe and photo and revealed this was all an issue of lighting. It turns out that while they turned up in huge numbers to answer grey, the majority of people were wrong. The shoe is actually pink and white.

Some are still arguing whether this was deliberately edited or not, while some just say it's the light conditions the photo was taken that affected what colour we see it.

There is some science behind this phenomenon that can go some way to explain how we got here in the first place. Neuroscientist Bevil Conway, who works at the National Eye Institute in the U.S., explained that people's brains were attempting to separate what they identified as colour cast by the source of light reflected by the surface of the shoe. He explains:

"Basically, your visual system is constantly trying to colour-correct the images projected on the retina, to remove the colour contamination introduced by the spectral bias in the light source"

"The sky is blue, but everything you see under a blue sky isn’t blue. This is because your visual system is pretty darn good at figuring out what part of the light that you’re seeing is caused by the light source, and what part is caused by the surfaces themselves. We only really care about the surfaces – this is the part of the light that tells us about objects. The color of the light itself is usually pretty meaningless."

"When you first look at it, after having looked at the pink version, your visual system is still adapted to the lighting conditions of the pink version," Conway says, "so you see the turquoise in the other version, and you attribute this to the shoe itself."

"But, after a while, your visual system adapts to the turquoise across the whole of that image and interprets it as part of the light source, eventually discounting it and restoring the shoe to the original pink version – or, at least, pinker."

So, even knowing all this - does it affect what you see? I must admit this whole thing has me questioning what colours I see versus what others see. Who knew the colour of a shoe could cause such a heated debate?