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Authoritative Madder

#911637
Notes

Authoritative Madder (#911637) 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°, 74%, 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 teal. For something softer, pull in its analogous neighbors on either side of the wheel.

HEX
#911637
RGB
rgb(145, 22, 55)
HSL
hsl(344, 74%, 33%)
HWB
hwb(344 9% 43%)
OKLCH
oklch(43.0% 0.156 12.7)
P3
color(display-p3 0.5213 0.1389 0.2215)
HSV
hsv(344, 85%, 57%)
LAB
lab(31.51% 50.52 13.95)
LCH
lch(31.51% 52.41 15.43)
CMYK
cmyk(0%, 85%, 62%, 43%)

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.

Madder
noun

Rubia tinctorum, the dyer's madder — the root pigment that fed European red textile production from antiquity until synthetic alizarin replaced it in 1869. Less brilliant than kermes, more lightfast than safflower, madder-dyed wool was the workhorse red of Persian carpets, British redcoats, and Turkish kilim. The color carries that history: a warm, slightly orange red with the matte finish of cloth rather than glaze.

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.

#911637
Original
#3b3a37
Protanopia
#5a5334
Deuteranopia
#9f0025
Tritanopia
#333333
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
8.85:1
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
2.37:1

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
##911637
Display P3
Display P3
color(display-p3 0.5213 0.1389 0.2215)
P3 has subtle headroomOKLCH chroma 0.156

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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