Heian era
Wisteria & Indigo— 藤と藍
The soft lavender of wisteria blossoms against deep indigo.
#1C3D5A
blue · 2 palettes
Ai
藍
True indigo
About Ai
Ai (藍) is a deep, muted blue tone. Its hex value is #1C3D5A — that is
RGB 28, 61, 90, or HSL 208°, 53%, 23%.
True indigo.
It holds 11.3:1 contrast against white, so Ai works best for body text, headings, and UI labels. (On white it scores 11.3:1; on black 1.9:1.)
Across Sanzo Wada's 1933 Dictionary of Color Combinations, Ai appears in 2 combinations — most often paired with Fuji, Gofun and Ukon.
The story of Ai
Ai (藍) is indigo — the deep blue dyed from the leaves of Polygonum tinctorium (Japanese indigo plant) through a fermented vat dye process that takes months to set up and decades to master. By the Edo period, ai was the workhorse blue of the entire country: samurai under-armour, merchant work clothes, futon covers, noren shop curtains. Whole towns built their economy around ai dyeing.
The colour reads everyday Japanese in a way no other blue does — closer to denim than to ultramarine, closer to navy than to cobalt, with a slight green undertone and the textile-dye depth that synthetic blues never quite match. Modern usage: heritage food brands, craft-goods packaging, anywhere that wants to read as 'old Japan' without reading as 'tourist Japan.'
Working note: The textbook ai pairing is with kinari (unbleached cream) — the indigo-and-cream of Edo-period workwear. Reads instantly traditional + warm + grounded.
See Ai in the Japanese Color Glossary →
How often colors like this recur across the 348 plates — the data analysis →
Colours that go with Ai
From a standard colour wheel, Ai anchors these four classic schemes. Each swatch is computed from its exact hue, so every hex is a real, usable pairing.
Complementary
#1C3D5A #5A391C
the hue directly opposite — the highest-contrast pairing, good for a single bold accent.
Analogous
#1C3D5A #1C5A58 #1C1E5A
the two neighbours on the wheel — a calm, cohesive scheme that feels effortless.
Triadic
#1C3D5A #5A1C3D #3D5A1C
two hues an even third of the wheel away — balanced and lively without clashing.
Split-complementary
#1C3D5A #5A1C1E #5A581C
the two colours either side of the complement — the contrast of a complement, softened.
How to use Ai
Ai is a deep, muted tone (HSL 208°, 53%, 23%), which makes it a grounding background or strong accent. For text it passes WCAG AA for body text against a light background (11.3:1) — safe for paragraphs, buttons and labels. When you do set type on it, use light lettering. Pair it with its complement (#5A391C) for a focal accent, or with its analogous neighbours (#1C5A58 and #1C1E5A) for a quieter, harmonious feel.
Palettes with Ai
Ai appears in 2 combinations from the archive. Each pairing reveals how the same color shifts character depending on its neighbours. For how usage like this compares across the whole dictionary, see the data analysis of all 348 plates.
From the archive
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