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Adamant Madder

#870b2c
Notes

Adamant Madder (#870B2C) 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°, 85%, 29%) 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
#870b2c
RGB
rgb(135, 11, 44)
HSL
hsl(344, 85%, 29%)
HWB
hwb(344 4% 47%)
OKLCH
oklch(40.1% 0.153 15.1)
P3
color(display-p3 0.4844 0.1078 0.1804)
HSV
hsv(344, 92%, 53%)
LAB
lab(28.31% 49.43 16.66)
LCH
lch(28.31% 52.16 18.62)
CMYK
cmyk(0%, 92%, 67%, 47%)

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.

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.

#870b2c
Original
#35332c
Protanopia
#534b28
Deuteranopia
#95001b
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
9.93:1
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
2.11:1

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
##870B2C
Display P3
Display P3
color(display-p3 0.4844 0.1078 0.1804)
P3 has subtle headroomOKLCH chroma 0.153

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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