What Color is that Dress? Why Color Isn't Always What You Think.

Because all the cats have gone to sleep, the Internet has blown up with this meme...

what color is this dress pic.twitter.com/RY7PVXwAkd

— my own sleeves (@grlaImighty) February 26, 2015

For most of us, the answer seems like a no-brainer: it's white and gold (and ugly). How is this even a controversy? And why are some people infuriatingly insisting on something that's so obviously not true?

It's an important question because it turns out your brain (and photography) is tricking you: that dress is blue and black (and about a quarter of you just said "no duh").

First, the tricks of photography (there are two). As a wedding photographer I spend a lot of time thinking about colors. What's the color story of your special day? How saturated should the colors of an image be? What colors grab the eye in an image and help me best tell the story of your wedding? After your wedding day, when I'm editing the photographs, I also spend a lot of time considering what photographers call "color balance."

Color balance (sometimes called white balance) is the delicate tweaking of colors in an image to ensure that whites (and grays) are rendered correctly (which, you can imagine, is very important for a wedding dress). I have to do this because different kinds of lighting can have dramatic effects on colors - sunlight tends to show off colors accurately, while objects in shadow are a little blue (remember this for later), and fluorescent or tungsten lighting can add warmth to images (by adding in more yellow). How is this relevant to the picture above? Well, if you look carefully in the original image, you'll notice that the light is a little too yellow. This means that for the whites to be closer to neutral, the whole image needs to have more blue.

The second part of the illusion is the exposure - or how much light has been let into the picture. Broadly speaking, exposure is broken up into three parts in a photograph: highlights (the brightest areas), mid-tones and shadows (the darkest areas). In this photo you can see that the highlights are cranked up so much that they're 'blown out' (meaning there's no real image, just a bunch of white pixels). The severity of the exposure will also tend to wash out a lot of the colors and play a few chromatic tricks.

Now this next correction requires an assumption - that the photograph is being taken indoors in relatively even store lighting. I think it's a safe assumption and you should trust me because I'm a New England wedding photographer, so I know bad indoor lighting. To correct this that means we need to make the whole image a lot darker, so we can start to recover information from those really bright patches. Here's what happens when you start to make these basic corrections...

From Left to Right: We start with the original image and then work on the color balance by adding more blue. The effect is subtle until we make the image darker to correct the exposure, and the corrected image shows a black and blue dress.

The second part of the illusion comes from your brain. Now, I am not a scientist so the following is just a cartoon sketch of what's going on when that Rube Goldberg Machine in your skull looks at this picture.

Crudely speaking, your brain doesn't really see the world - it constructs a model of the world based on input from your senses and a lot of guesswork. 90 percent of the time your brain is spot on, but when it guesses wrong that's when you start to see things a little funny like faces in trees, or hear words inside of random static (a phenomenon known as pareidolia). It's the same with color, your brain is just guessing and sometimes its guesses can be effected by context, mood and even the power of suggestion. This can lead to a whole series of illusions and for a better explanation (and some great examples) you can check out this presentation by neuroscientist and artist Beau Lotto (warning TED talk opens in new window).

So what's the trick here? Remember when I said that objects in shadows tended to look a little blue? Because the background is so bright, your brain is interpreting the blue in the dress as a shadow, so to make sense of the image your brain tells you that the blue is really white. But how does black become gold? As with the blue, the bright exposure washes the color out (leaving gray-green), and the yellow cast of the image turns that gray-green into brownish gold.

Once again, Ryan Richardson Photography (and science) has brought peace back to your relationship (both of you were kind of right?), so you probably owe us a call when you start planning your wedding.

Ryan Richardson is a Massachusetts wedding photographer serving Boston and New England. He infrequently writes on topics related to weddings, boudoir, portraiture and random snatches of science.