Late last night, I saw a Facebook post with the picture of a dress. The dress was blue and black. The blue was a deep, pretty blue – kind of a dark royal, but maybe a tad purple-y. The black was one of those blacks that could maybe be a really deep brown if you looked at it closely enough, but if you were forced to call it you’d probably say black.

Years ago, our oldest son came into the kitchen with a profoundly amazed look on his face. “Mom, Dad – I just thought about something. We might not see the same thing when we look at something. I mean, when we both look at something and say ‘it’s red,’ I don’t know that the color it looks like to me is the same as the color it looks like to you. Your red could be my blue.” This led to some wonderful discussions around the dinner table. We talked about how people can perceive and interpret things differently. How we never know for certain what is in someone else’s head. We looked at all sorts of optical illusions on the computer and in books. We discussed how an outline could be seen as a vase or as two faces in profile. How two lines that were exactly the same length could be made to look different with certain contextual cues.

But with all of this, the one thing we came back to was that everyone could at least be consistent in their labeling, even if their internal interpretations were different. No matter how we perceive blue, we know to label it as blue. The contextual clues to lengths of lines or shades of gray in shadows are pretty much universal. We can all flip the vase view to a face view, and vice versa. There is consistency, and we can see how our minds can be tricked with subtleties.

And then there was the picture of the dress. It wasn’t subtle. The colors were unambiguous. And I read the introduction to the picture that my friend had posted – she said her family was freaking out because all of them saw a black and blue dress, but she was seeing a gold and white dress. I read through the comments of her friends, and there was actually a split – people were either seeing black and blue or gold and white.

I called my husband over to the computer and asked him the colors of the dress. He looked at me strangely, and said “white and yellowish-gold. Why are you asking me?”

This man and I have been married 21 years. We chose dish colors together. We’ve picked car colors, party colors, ties, shirts, dresses – we are consistent in our color labeling.

And yet.

We both thought that the other was teasing. That the other was in on some hoax.

We called in our younger two boys. The youngest came in first. They both saw blue and black.

We then Googled “blue and black or white and gold dress” to see if there was an explanation out there. We found a few articles – something describing different types of cones (the retinal cells which pick up color), something talking about light settings on computer screens, all sorts of hypotheses. This picture had gone viral and everyone was trying to wrap their minds around it.

While looking through these articles, explanations, comments, and hypotheses, something even weirder happened. As I looked at the picture, the blue lightened considerably. The black lightened to a light, golden brown. Before too long, I was seeing a clearly gold and white dress. Our sons were still seeing blue and black.

Today, I still see basically white and gold, but it is a blueish white or light blue, and a darkish gold. Try as I might, I no longer am able to see the deep blue and slightly brownish black I had first perceived. Nor do I see the distinct white and gold I briefly perceived. What I see now is ambiguous.

The hypotheses will need to be tested as to why this dress photo defies our normal understanding of at least labeling consistency (even if not internal perception uniformity). Of the explanations I’ve seen so far, it makes sense that it will turn out to be some sort of contextual interpretation.

But this flips some very basic presumptions on their head. We presume that those of us with intact color vision have consistent labeling of basic colors. We presume that when we see something with our own eyes we know what we’ve seen, or at least our perception is consistent with specific known visual or psychological cues.

This picture obviously hits at the edge of some specific perceptual border. People either fall on one or the other side of that border. Some of us slip over that border and see it from the other side. And I am guessing that I’m not the only one now stuck on the line of ambiguity.

How many other things in this world and in our lives fall on such borders? What other visuals, aside from colors, have such lines of demarcation? What other senses might fall prey to such lines of distinction? What thoughts? What concepts?

This drives home deeply the importance of communication. Of consciously working towards empathy. Of telling people where you’re coming from. Of asking others what they feel, what they see, what they think.

We cannot presume.