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Authoritative Crimson

#b51f21
Notes

Authoritative Crimson (#B51F21) is a true red with a vibrant character. It holds its own as a focal accent, carrying visual weight without tipping into neon territory. Its HSL profile (359°, 71%, 42%) places it in the balanced band at a mid lightness. It works across type, buttons, and borders, saturated enough to feel deliberate but balanced enough to not fight the rest of the palette. For a confident two-color system, pair it with its complementary cyan. For something softer, pull in its analogous neighbors on either side of the wheel.

HEX
#b51f21
RGB
rgb(181, 31, 33)
HSL
hsl(359, 71%, 42%)
HWB
hwb(359 12% 29%)
OKLCH
oklch(50.0% 0.185 26.6)
HSV
hsv(359, 83%, 71%)
LAB
lab(39.44% 57.55 38.73)
LCH
lch(39.44% 69.37 33.94)
CMYK
cmyk(0%, 83%, 82%, 29%)

Etymology

Authoritative
adjective

Latin auctōritāt-, authority — adjectival suffix -ive. As a color modifier, authoritative implies a saturated-and-formal-imperative quality where the hue carries decisional weight and institutional credibility. Sits at the bold-and-authoritative end of the grid, parallel to commanding and magisterial in usage.

Crimson
noun

From the Old Spanish cremesin, itself from the Arabic qirmiz — the kermes scale insect, dried and ground into a brilliant carmine dye prized in the medieval Mediterranean. For centuries the most expensive red on a draper's shelf, reserved for cardinals, kings, and the cloth that gave English the word crimson. Cooler than scarlet, deeper than rose; the color of pomegranate seeds and a serious occasion.

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.

#b51f21
Original
#51481f
Protanopia
#756819
Deuteranopia
#c80022
Tritanopia
#3f3f3f
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).
AAon White
6.60:1
The quick brown foxSample body text at normal size. The wcag minimum for body contrast is 4.5:1 (AA) or 7:1 (AAA).
AA Largeon Black
3.18:1

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