This dress is actually from British retailer Roman Originals. This dress is blue and black. It is low quality photograph was taken by the Tumblr Blogger. It flummoxed all the viewers and many hilarious memes were made out of it.
How it is seen differently?
It is clear that the human eyes are evolved to see the colors with the main source of light being sunlight. Objects as seen by us are colored because of the bouncing back of colors and then back on our retinas. Our brain reciprocates to it. It registers the actual color of light source and then subtracts the bounced back color from it. Let us imagine another example- an object of yellow color on white object. According to our brain the yellow colored source is landing and reflecting on the surface of white object and our brain would try to get it and then ignore it.
Human eyes evolve between the actual color and the color of light source
We are evolved to see the full spectrum of colors of light as we are used to see the sunny colors shifting from sunrise to sunset. It is white bluish in middle of the day while yellowish red at the end of the day. The visual system of humans gets the actual reflectance information and ignores the illuminant information as said by the neuroscientist Jay Neitz of University of Washington.
Few Brains Subtract Blue while some subtract the Yellowy golden
The blue dress created much havoc. Some brains are subtracting the bias color as generated by the light source while some brains are ignoring the bluish tones. Hence they tend to see it as white and golden. While few brains are missing the yellow golden they see it as blue and black.
The Different Colors
The weird point is that initially people see it white and gold but then the enhanced vision make it look different color. It simply shows how the human brains process in context of colors. There are other optical illusions as well.
Neitz said that he had studied individual differences in color vision for 30 years and this was one of the biggest individual differences he had seen.