Blue is the world’s favorite color. Ask people in country after country to name theirs and blue comes out on top. It’s also one of the hardest colors to find in nature, and for most of history it was one of the hardest for people to make.
We woke up wanting a whole lot of blue this morning.
So we went looking for it in seventeen years of Moss & Fog instead. We found glaciers that glow from the inside, a hotel carved from ice, a great white shark named Deep Blue and a photo of our entire planet taken from 6 billion kilometers away.
So here’s a whole post of blue. We start overhead and sink, chapter by chapter, to the bottom of the sea, then pull way, way back. Keep an eye on the page as you scroll. It gets deeper as you go!
This story is built to be seen on the web, where the page sinks from sky blue to the deep. Open it online for the full trip.
Explore by color
Seventeen Years, Sorted by Blue
Our homepage has a color picker. We looked at the lead image of every story going back to 2009 and noted the color that fills each frame. Pick Blue and the archive hands you salt flats, ice hotels, deep-sea jellies and a cloud that floats over your desk. Tap More in blue as many times as you like. It never runs out.
Browse the whole archive by Blue
01 · Overhead
Why the Sky Picked Blue
Start with the obvious one. On a clear day the whole dome above you is blue, and it took scientists until the late 1800s to really explain why. The answer came from the British physicist Lord Rayleigh, and it’s still one of our favorite bits of science.
The artists in our archive love that dome. Murray Fredericks once carried a big mirror out onto Lake Eyre, the flattest place in Australia, and photographed the sky inside the sky. Samir Belhamra makes landscapes so spare and so blue they feel like holding your breath.

Why it’s blue
Sunlight is every color mixed together. When it hits the air, tiny molecules of nitrogen and oxygen scatter the short blue waves much more than the long red ones, so blue light comes at us from every direction. Violet scatters even more, but the sun sends less of it and our eyes aren’t as tuned to it. So we get blue.
02 · Frozen
Ice That Glows From Inside
Snow is white. So why is a glacier blue? It’s the same water, just packed differently, and the difference is all about how far light can travel before it comes back out.
Lake Baikal in Siberia holds about a fifth of all the fresh, unfrozen water on the surface of the planet, and in winter it turns to clear blue ice so thick people drive across it. Kristina Makeeva photographed a gown made of it, or near enough. It still gives us chills (sorry).

Why it’s blue
Glacier ice is squeezed so hard that most of its air bubbles get pushed out. Light travels deep into it, and on the way the ice soaks up the red end of the spectrum. What makes it back to your eye is blue. Snow is full of tiny bubbles and edges that bounce every color straight back before any of it gets absorbed, so it looks white.
03 · The surface
The Sea Keeps the Blue
Most people assume the ocean is blue because it reflects the sky. That helps, especially on a sunny day. But the bigger reason is the water itself.
Off the coast of Australia, someone filmed a wave that does something very strange. Several waves meet over a reef and, instead of breaking forward, the water shoots straight up. We’ve watched it more times than we’d like to admit!

Why it’s blue
Water absorbs red light first, then orange and yellow. A few meters down, a red swimsuit already looks brownish. Blue is the color that survives longest on the way down, and the color that bounces back up to us. Clear water over white sand, like you see in the tropics, is blue for the same reason, with nothing in it to muddy the color.
04 · Below
Where Blue Goes Dark
Keep sinking and the blue gets richer, then dimmer, then gone. The deep sea is the largest living space on Earth, and almost all of it sits in the dark.
Photographer Steve Haining and model Ciara Antoski set a world record shooting this picture beside a shipwreck, 163 feet down. That’s about 50 meters. Look at what’s left of the light by then. Nearly all of it is blue.

Why it goes dark
Below about 200 meters only a faint blue glow remains, and below 1,000 meters there’s no sunlight at all. Lots of deep-sea animals are red, which in blue-only light looks black, a handy way to disappear. Many others make their own light, and it’s almost always blue or blue-green, the colors that travel farthest through seawater.
05 · By hand
Blue Is Hard to Make
The strange thing is that for all the blue in the sky and sea, living things almost never make it themselves. Very few plants or animals produce blue pigment. A blue jay’s feathers and a morpho butterfly’s wings get their color from tiny structures that scatter blue light, the same trick the sky uses. Crush a blue jay feather and the blue disappears.
People had a hard time too. Five blues tell most of the story, and the newest one was discovered about an hour and a half down the road from us.
Egyptian blue About 5,000 years ago
The first color people made from scratch, by heating sand, copper and lime. It glows under infrared light, which is how museums still find faint traces of it on ancient statues.
Ultramarine The Renaissance
Ground from lapis lazuli mined in the mountains of Afghanistan. It could cost more than gold, so painters saved it for the most important robes in the picture. The name means beyond the sea.
Prussian blue 1704
Made by accident in a Berlin lab. It was cheap and strong, and it traveled all the way to Japan, where Hokusai used it on The Great Wave.
International Klein Blue 1960
Yves Klein mixed ultramarine into a clear binder so the paint stayed as bright as the dry powder, then registered his formula in Paris.
Artists keep coming back to it, too. Ian Berry makes whole scenes, swimming pools and all, out of cut and layered denim. And Lena Vargas drew an entire alphabet out of coral and sea creatures.
A little blue to keep
Three small blue things from our shop.
06 · From far away
One Pale Blue Dot
After all that sinking, here’s the view from the other direction. On February 14, 1990, as Voyager 1 headed out of the solar system, NASA turned its camera back toward home at the urging of Carl Sagan. Earth showed up from about 6 billion kilometers away as a speck smaller than a single pixel, caught in a scattered beam of sunlight.
Sagan called it a pale blue dot, and the name stuck. NASA cleaned up the image for its 30th anniversary in 2020. That’s the version below, and our story on it is one we come back to often.

Every blue in this post is on that speck, every sky and glacier and wave and deep-sea glow. We hope you find some of it today, wherever you are. And if your sky won’t cooperate, the archive will.



























