On Friday, the internet went crazy about the colours of this dress. About 50% of people saw the dress in the image above as blue and black while the other 50% could only see white and gold.
The actual dress is blue and black as seen in the photo below. The exposure of the photograph above makes some people focus on the contrast and see gold and white.
CP24 feature one expert explanation here, and claims the colour is in the eye of the beholder. Since colour is a psychological phenomenon, this makes sense. What is still puzzling is why approximately 50% of people interpret the image one way and the other 50% another way.
Just to see, I played around with both images in Photoshop to try and create both colour schemes, here are some comparisons:
The image of the dress on the far right above has the most extreme exposure and the most gold and white and has the following colours using the eyedropper tool in Photoshop:
The whitest part of the dress is light blue.
The lightest part of the gold is seen here- and is a mid-tone.
For the original image of the dress that caused all the hype, the colours are similar but darker:
The whitest/lightest part of the dress is a mid-tone blue.
The lightest part of what some people saw as gold is a dark-tone brown.
You can see in these colour comparisons how the dress has colours in the mid range between black at the bottom (the actual colour of the dress) and gold at the top (the over-exposed photo of the dress); and dark blue at the bottom of the other Colour Picker image and light blue leading to white at the top.
The psychology comes into it when the individual chooses to veer towards the lighter side or the darker side and whether they are sensitive to the overexposure of the image or not. If they are sensitive to the overexposed nature of the image, the mind will colour-correct to the blue-black colour scheme. However, if the mind accepts the photo as regular light, they will see the gold-white colour scheme. The photo of "the dress" seems to be a new addition to the history of optical illusions.