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Certain Madder

#ac1c32
Notes

Certain Madder (#AC1C32) is a true red with a warm character. It leans warm, pulling light toward red, orange, and yellow. Naturally inviting, it suits editorial and hospitality contexts. Its HSL profile (351°, 72%, 39%) 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 teal. For something softer, pull in its analogous neighbors on either side of the wheel.

HEX
#ac1c32
RGB
rgb(172, 28, 50)
HSL
hsl(351, 72%, 39%)
HWB
hwb(351 11% 33%)
OKLCH
oklch(48.4% 0.177 19.9)
HSV
hsv(351, 84%, 67%)
LAB
lab(37.54% 56.37 26.01)
LCH
lch(37.54% 62.09 24.77)
CMYK
cmyk(0%, 84%, 71%, 33%)

Etymology

Certain
adjective

Latin certus, fixed / sure — sharing root with English concern and certify. As a color modifier, certain implies a saturated-and-unambiguous quality where the hue declares its character without hesitation. Sits at the bold-and-confident end of the grid, parallel to assured and decisive 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

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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.

#ac1c32
Original
#4a4532
Protanopia
#6d632d
Deuteranopia
#bd0026
Tritanopia
#3c3c3c
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
7.08:1
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
2.97:1

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