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Adamant Shu

#a4032f
Notes

Adamant Shu (#A4032F) is a deep red 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 (344°, 96%, 33%) places it in the highly saturated band at a dark lightness. Best used in small doses, like logos, CTAs, focus rings, or highlight text, where its saturation becomes a feature rather than noise. For a confident two-color system, pair it with its complementary teal. For something softer, pull in its analogous neighbors on either side of the wheel.

HEX
#a4032f
RGB
rgb(164, 3, 47)
HSL
hsl(344, 96%, 33%)
HWB
hwb(344 1% 36%)
OKLCH
oklch(45.7% 0.181 17.5)
HSV
hsv(344, 98%, 64%)
LAB
lab(34.33% 58.34 23.60)
LCH
lch(34.33% 62.93 22.03)
CMYK
cmyk(0%, 98%, 71%, 36%)

Etymology

Adamant
adjective

Greek adámas, unconquerable — derived from a- (not) plus damnan (to subdue). As a color modifier, adamant implies a saturated-and-rock-hard quality where the hue maintains diamond-hard pigmentation. Sits at the bold-and-resilient end of the grid, parallel to indomitable and ironclad in usage.

Shu
noun

Vermillion in Japanese — specifically the cinnabar-derived pigment used since the Heian period to paint Shinto torii gates, temple beams, and the lacquer of imperial seals. The color refers to a freshly painted Inari Shrine torii: a saturated, slightly orange red with the high gloss of layered urushi lacquer. Brighter than crimson, deeper than tangerine, with the sacred-architectural weight of a color reserved for thresholds between human and divine.

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.

#a4032f
Original
#403d2f
Protanopia
#655c2a
Deuteranopia
#b5001b
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
7.98:1
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
2.63:1

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