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Smouldered Idanthrene

#12276f
Notes

Smouldered Idanthrene (#12276F) is a deep blue with a jewel character. It carries the deep, saturated richness of a gemstone. Authoritative and slightly formal, it works well for type and heavy UI elements. Its HSL profile (226°, 72%, 25%) places it in the balanced band at a dark lightness. It works well as a headline, icon, or deep background in an otherwise light layout, pairing cleanly with cream, bone, and warm neutrals. For a confident two-color system, pair it with its complementary amber. For something softer, pull in its analogous neighbors on either side of the wheel.

HEX
#12276f
RGB
rgb(18, 39, 111)
HSL
hsl(226, 72%, 25%)
HWB
hwb(226 7% 56%)
OKLCH
oklch(30.9% 0.127 266.2)
HSV
hsv(226, 84%, 44%)
LAB
lab(18.92% 21.12 -43.91)
LCH
lch(18.92% 48.73 295.68)
CMYK
cmyk(84%, 65%, 0%, 56%)

Etymology

Smouldered
adjective

From Old English smolderian, to burn slowly — past-participle of smoulder. As a color modifier, smouldered implies the deep glowing-dark quality of fire-warmed embers, where the underlying hue retains warmth even at low lightness. Sits at the deep-and-warm end of the grid, somewhere between charred and burnt.

Idanthrene
noun

The trade name for vat blue synthetic dyes — particularly Idanthrene Blue RS (BASF, 1901), a polycyclic aromatic dye that displaced indigo for many industrial textile applications. The color refers to Idanthrene-dyed industrial cotton: a saturated, slightly cool deep blue with the matte finish of synthetic-pigment-and-cotton.

Closest matches

The nearest named color in three reference sources, ranked by perceptual distance (ΔE76 in CIELAB). ΔE < 1 is imperceptible to most viewers; ΔE > 10 is clearly different. When two sources point to the same hex they’re merged into one tile; click any to open that color’s page.

Variations

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Harmonies

Accessibility

Color-vision simulation

How this color appears to viewers with the four major color-vision-deficiency types. Computed via the Machado (2009) physiologically-based model. If a tile matches the original, the color reads the same to that viewer.

#12276f
Original
#003271
Protanopia
#002a6e
Deuteranopia
#003a47
Tritanopia
#282828
Achromatopsia
WCAG contrast

The color used as foreground text against pure white and pure black, with the contrast ratio and WCAG 2.1 grade. Aim for AA (4.5:1) for body text and AA Large (3:1) for 18 pt+ headlines; AAA (7:1) is the gold standard for long-form reading surfaces.

The quick brown foxSample body text at normal size. The wcag minimum for body contrast is 4.5:1 (AA) or 7:1 (AAA).
AAAon White
13.59:1
The quick brown foxSample body text at normal size. The wcag minimum for body contrast is 4.5:1 (AA) or 7:1 (AAA).
Failon Black
1.55:1

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