There is a blue in ukiyo-e that stays with you.
Deep, consuming — the kind you fall into rather than simply look at. A blue that fills crashing waves, dissolves into rain-soaked skies, sits at the edge of early morning. Whatever form it takes, something about ukiyo-e’s blue tends to linger long after you’ve left the print behind.
Where did it come from? How did it reach the hands of Japan’s woodblock artists? The answer turns out to be a story that crosses continents and centuries — and knowing it changes the way you see the color.
① The Indigo That Came Before
Long before ukiyo-e, Japan lived with ai — indigo.
Kimono, noren curtains, hand towels, everyday objects of every kind — indigo dyeing was woven into the fabric of Edo life. To walk through the streets of Edo was to walk through indigo. It was the color of ordinary days.
But natural indigo had its limits. As a pigment for woodblock printing it was difficult to work with, and the blues in early ukiyo-e tended toward something muted, even a little dull. Artists wanted more — a blue with presence, with depth — and for a long time they had no way to get there.
② Prussian Blue Arrives
In the 1820s, a new pigment began to be imported into Japan.
Bero-ai — Prussian blue. Discovered by accident in early-eighteenth-century Germany — by a maker chasing a red dye, of all things — it produced a blue of extraordinary vividness and transparency, something no natural pigment available in Japan could match.
For a long time it was rare and costly. But it reached Japan through the Dutch trading post at Nagasaki, and once Chinese workshops began producing it in bulk, the price fell far enough for Edo’s print publishers to take a serious interest. The name tells the story of its travels: bero is Edo dialect for “Berlin.”
It changed everything.
Hokusai’s Thirty-Six Views of Mount Fuji, begun in 1831, is saturated with it. The publisher behind the series, Nishimuraya Yohachi, made a bold wager: the first prints were issued as aizuri-e — printed almost entirely in shades of blue — a deliberate way of showing Edo exactly what this new color could do. It worked. The series announced a new visual world — clear, luminous, unmistakably blue — and Edo responded immediately. The phrase bero-ai hayari, “the Prussian blue craze,” entered the language. A German accident had become an Edo obsession.


And it didn’t stop at landscapes. Beauty-print artists were soon issuing aizuri-e of their own — fashionable courtesans rendered almost entirely in the new blue.

③ Hokusai’s Blue, Hiroshige’s Blue
What’s remarkable is how differently two artists could use the same pigment.
Hokusai’s blue is bold and declarative. In The Great Wave, it fills the churning depths of water and the shadowed underside of foam, pressed into the paper in layers that move from near-black to the palest grey-blue sky. He understood that Prussian blue could be infinitely modulated by concentration, and he used the full range — all of it in one image.
Hiroshige’s blue is something else entirely. Through a printing technique called bokashi — a gradation applied while the ink is still wet — he dissolved blue into atmosphere. The dawn sky in Fifty-Three Stations of the Tōkaidō, the rain-blurred distances of One Hundred Famous Views of Edo, the particular quality of air before and after a shower: Hiroshige rendered all of it in blue so soft it seems to breathe. This quality became so characteristic that it acquired its own name: Hiroshige Blue.
The same pigment. Two completely different blues. Once you see the distinction, you start looking for it in every print you encounter.


④ Van Gogh Used This Blue Too
There is one more turn in the story.
Van Gogh’s debt to ukiyo-e is well documented — he studied Japanese prints obsessively, copied them in oil, wrote about them to his brother Theo. What is less often noted is that Van Gogh was also a heavy user of Prussian blue. The sky in The Starry Night, the walls in The Bedroom at Arles — the same pigment that gave Hokusai his wave and Hiroshige his rain is there in Van Gogh’s most celebrated canvases.
Hokusai and Hiroshige used Prussian blue to make ukiyo-e. That ukiyo-e reached Van Gogh. Van Gogh painted his response in Prussian blue. Three artists, one pigment, a chain of influence that crossed Japan and Europe — all without any of them quite knowing the whole shape of it.
A color discovered by accident in Germany had quite a journey ahead of it.

⑤ The Indigo That Continues
Natural indigo dyeing never disappeared. Across Japan, craftspeople still grow indigo and dye with it by hand, in ways that have not fundamentally changed since the Edo period. The arrival of Prussian blue never pushed it aside — the two simply went on existing side by side. The complex, living depth of natural indigo is a thing entirely its own, and the hands doing this work today are connected, through an unbroken line, to the hands that dyed the kimono in Utamaro’s beauty prints.


Natural indigo dyeing, still practiced by hand across Japan today. Photos via PhotoAC.
Two blues, running in parallel across the centuries.
A Final Thought
The blue in Hokusai’s wave and the blue dissolving through Hiroshige’s skies both trace back to the same pigment — one discovered by accident, traveled east, and transformed what Japanese printmaking could look like.
The next time you find yourself in front of a ukiyo-e print, pay attention to its blue. Is it Hokusai’s blue — dense, structural, present? Or Hiroshige’s — atmospheric, breathing, on the edge of disappearing? They are not the same blue, even when they are made of the same thing.
The name Aiiro — 藍色, “indigo color” — is where this blog takes its name from. It felt like the right place to begin.
References
- Philip Ball, Bright Earth: Art and the Invention of Color, Farrar, Straus and Giroux, 2001
- The Metropolitan Museum of Art, “Prussian Blue in Japanese Prints” — metmuseum.org
Image Credits
- Cover & Section ②: Katsushika Hokusai, Kajikazawa in Kai Province (Kōshū Kajikazawa), from Thirty-Six Views of Mount Fuji, c. 1830–32 — Public domain via The Metropolitan Museum of Art
- Section ②: Katsushika Hokusai, The Great Wave off Kanagawa, from Thirty-Six Views of Mount Fuji, c. 1831 — Public domain via Wikimedia Commons
- Section ②: Keisai Eisen, Hana-murasaki of the Tamaya, c. 1830 (aizuri-e) — Public domain via Brooklyn Museum / Wikimedia Commons
- Section ③: Utagawa Hiroshige, Night View of Saruwaka-machi, from One Hundred Famous Views of Edo, 1856 — Public domain via Brooklyn Museum / Wikimedia Commons
- Section ③: Utagawa Hiroshige, Sudden Shower over Shin-Ōhashi Bridge and Atake, from One Hundred Famous Views of Edo, 1857 — Public domain via Wikimedia Commons
- Section ④: Vincent van Gogh, Bridge in the Rain (after Hiroshige), 1887 — Public domain via Wikimedia Commons
- Section ⑤: Natural indigo dyeing — photos via PhotoAC

