Also known as: IKB
An intense ultramarine blue developed and popularised by the artist Yves Klein in 1960.
Similar to
Colours in photographs vary with lighting, material, camera processing and screen calibration — the named colours below are visual approximations, not exact measurements.

Holi is defined by a mix of many colours rather than any single one — historically made from natural plant-based dyes, now often synthetic.
This photograph was taken in low, warm indoor light, which shifts the true powder colours; an automated whole-frame scan is dominated by dark shadow rather than the vivid streaks that are the actual subject, so the palette above was hand-picked from the coloured powder itself.Photo: “Holi powders” by Andrea, CC BY 2.0, via Wikimedia Commons.

A vivid blue-violet can appear in a Holi powder mix as one of many celebratory colours, while a similar tone might carry an entirely unrelated meaning in a different tradition's religious vestments or mourning custom — the colour itself doesn't carry the meaning; the specific tradition and context does.
In practice: This is a genuinely useful habit when learning about any colour's cultural associations: always ask which specific tradition, region and occasion a claim is about, rather than assuming one meaning travels with the colour everywhere.
Photo: “Holi powders” by Andrea, CC BY 2.0, via Wikimedia Commons.
Calculated from International Klein Blue’s position on the HSL wheel (hue 223°, saturation 100%, lightness 33%). Colour-wheel pairings are a design convention, not a guarantee: check any pairing in the light and material you will use it in.
Complementary
Opposite hues (180° apart) for maximum hue contrast: hue 223° → 43° on the HSL wheel.
Analogous
Neighbouring hues on the colour wheel for a low-contrast, harmonious feel: hue 223° → 193° on the HSL wheel.
Analogous
Neighbouring hues on the colour wheel for a low-contrast, harmonious feel: hue 223° → 253° on the HSL wheel.
Triadic
Three hues evenly spaced around the colour wheel for balanced contrast: hue 223° → 343° on the HSL wheel.
Triadic
Three hues evenly spaced around the colour wheel for balanced contrast: hue 223° → 103° on the HSL wheel.
No curated profile yet
Split-complementary
The two hues bracketing the complement, for contrast with less tension: hue 223° → 13° on the HSL wheel.
Split-complementary
The two hues bracketing the complement, for contrast with less tension: hue 223° → 73° on the HSL wheel.
No curated profile yet
Tetradic
Four hues at 90° steps around the colour wheel for a rich, varied palette: hue 223° → 313° on the HSL wheel.
Tetradic
Four hues at 90° steps around the colour wheel for a rich, varied palette: hue 223° → 43° on the HSL wheel.
Tetradic
Four hues at 90° steps around the colour wheel for a rich, varied palette: hue 223° → 133° on the HSL wheel.
No curated profile yet
Monochromatic
Hue held at 223°, lightness 20% against this colour's 33%.
Monochromatic
Hue held at 223°, lightness 40% against this colour's 33%.
Monochromatic
Hue held at 223°, lightness 60% against this colour's 33%.
Monochromatic
Hue held at 223°, lightness 80% against this colour's 33%.
No curated profile yet
Persian Blue is the closest, at ΔE00 3.9 from international klein blue: 5 points lighter and 4 points more saturated. That is visibly different side by side, easily confused apart.
Cobalt Blue is next, at ΔE00 7.7 from international klein blue: 7 points lighter, 14 points less saturated and 8° round towards blue. That is clearly different, though many people would use one name for both.
Midnight Blue is next, at ΔE00 9.4 from international klein blue: 10 points darker, 18 points less saturated and 4° round towards red. That is clearly different, though many people would use one name for both.
Navy Blue is next, at ΔE00 11.0 from international klein blue: 13 points darker, 4 points more saturated and 7° round towards red. That is clearly different, though many people would use one name for both.
Distances are CIEDE2000 between catalogue reference values; lightness and saturation are CIELAB L* and C*. How to read a ΔE figure · Measure any two colours
Worked out from this colour’s own measurements — its lightness, saturation and undertone — rather than written for it. That is why the guidance differs from one colour to the next even when the two look similar.
This is a small-scale colour. At chroma 76 it holds attention easily, which is a strength on a cushion or a door and a liability across four walls.
At chroma 76 this is far above the level walls and large surfaces usually carry comfortably. It can be done deliberately, but it will be the room rather than part of it.
Chroma 76 is above the usual comfort level for secondary surfaces, so expect it to take charge. That is a legitimate choice in a room that wants a subject. On panelling, a chimney breast or an alcove this is semi-permanent — repaintable, but not casually.
Chroma 76 is above the usual comfort level for furniture, so expect it to take charge. That is a legitimate choice in a room that wants a subject. In a sofa or a cabinet this is one purchase you will live with, so it is worth seeing the piece in the actual room first.
Chroma 76 is above the usual comfort level for rugs, curtains and bedding, so expect it to take charge. That is a legitimate choice in a room that wants a subject. In rugs, curtains and bedding it is the cheapest commitment in the room to reverse, which makes it the right place to test a strong colour.
Chroma 76 is above the usual comfort level for trim and joinery, so expect it to take charge. That is a legitimate choice in a room that wants a subject. Trim is a small area but a long edge, so it reads more than its square metreage suggests.
Chroma 76 is exactly what an accent is for. The saturation that makes this difficult across a wall is the reason it works on a cushion, a door or a single chair.
At chroma 76 this is assertive enough that one appearance is a statement and three is a scheme. Use it once, deliberately, and let the rest of the room stay quiet.
How to distribute colour across a roomWhat colour temperature actually means · Why two bulbs at the same rating can differ
Opposite in undertone to Oak, Pine, Plywood and Light wood (ash, birch, beech), but 40–59 points apart in lightness or far enough round the hue circle that the difference reads as deliberate contrast rather than as a clash.
Opposed in undertone to Walnut, Dark wood and Reddish wood (mahogany, cherry, teak) with only 2–4 points of lightness to explain the difference, which is the combination the eye most often reads as an error.
The amount of timber matters as much as the tone: one piece is an accent, a floor plus joinery is the room’s dominant colour. More on working with wood tones
Shares the cool bias of Chrome and Stainless steel, so they agree about the temperature of the room, and 50–54 points of lightness keep them readable as separate from this colour.
Shares the cool bias of Black metal and sits within 19 points of it in lightness, so expect a quiet, tonal relationship rather than a contrast.
Shares the cool bias of Brass, Gold-tone and Copper, but at chroma 76 against materials that carry colour of their own, the two compete rather than combine. It works when this colour is confined to a small area and fails when both are large.
Metal carries more attention than its area suggests, so repetition matters more than the exact finish. More on metals and mixing them
History
2 documented associations apply to the blue family as a whole rather than to this shade: what is documented about blue.
Calculated directional adjustments. Some directions converge on the same result from this starting colour — shown as one merged card with an explanation, not repeated duplicates. Generated shades link to a curated profile only when one is close enough.
Lighter
Lightness increased
Darker
Lightness decreased
Warmer & Redder
Hue rotated toward warm (red/orange) From this starting colour, moving warmer and redder converges on the same calculated result.
Cooler
Hue rotated toward cool (blue)
Greener & Yellower
Hue rotated toward green From this starting colour, moving greener and yellower converges on the same calculated result.
Bluer
Hue rotated toward blue
More muted
Saturation softened
More saturated
Saturation increased This is close to the source colour itself — there is limited room left to move more saturated from here.
Approximate, from each printing condition’s published aim values; a printer’s own profile is the final word. See the full print gamut check.
CMYK is an approximate device conversion, not a calibrated print value — see methodology.
Convert this colour to another format →
Widely cited reference value associated with Yves Klein's formulation.
vs. white text
10.69:1 — AAA
vs. black text
1.96:1 — fails
Confidence: medium · Qualification: identity_only, technically_qualified, curated_profile_eligible, search_index_eligible, comparison_eligible
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