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Suffocating Tarbuttite

#371c8a
Notes

Suffocating Tarbuttite (#371C8A) is a deep indigo 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 (255°, 66%, 33%) 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 lime. For something softer, pull in its analogous neighbors on either side of the wheel.

HEX
#371c8a
RGB
rgb(55, 28, 138)
HSL
hsl(255, 66%, 33%)
HWB
hwb(255 11% 46%)
OKLCH
oklch(34.5% 0.167 284.7)
P3
color(display-p3 0.2012 0.1149 0.5199)
HSV
hsv(255, 80%, 54%)
LAB
lab(21.86% 42.07 -56.14)
LCH
lch(21.86% 70.16 306.85)
CMYK
cmyk(60%, 80%, 0%, 46%)

Etymology

Suffocating
adjective

Latin suffocāre, to choke — present-participle of suffocate. As a color modifier, suffocating implies a deep-and-overwhelming-and-pressing quality where the hue overwhelms the eye's capacity to discern surface detail. Sits at the deep-and-overwhelming end of the grid, parallel to smothering with breath-restricting register.

Tarbuttite
noun

Rare zinc-phosphate mineral first described from the Broken Hill lead-zinc deposits of Zambia in 1907, also found at Reaphook Hill in South Australia. Tarbuttite color refers to a deep-violet Broken Hill tarbuttite crystal cluster: a saturated, slightly cool deep blue-violet with the glassy finish of zinc-phosphate mineral. Named for Percy Coventry Tarbutt, an early-20th-century mining-company director.

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

Click any swatch to explore

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.

#371c8a
Original
#00378d
Protanopia
#003188
Deuteranopia
#053c53
Tritanopia
#2a2a2a
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
12.39:1
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
1.70:1

Wide gamut

Display P3 representation

The CSS Color 4 wide-gamut form of this color. Both swatches render the same color on every display — the P3 form only diverges from sRGB when a designer pushes channels outside sRGB's reach.

sRGB hex
sRGB hex
##371C8A
Display P3
Display P3
color(display-p3 0.2012 0.1149 0.5199)
P3 has subtle headroomOKLCH chroma 0.167

Moderately saturated colors gain a small bump in P3 — the difference is usually visible side-by-side on wide-gamut hardware but won't change the character of the color.

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