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Resolute Castor Crimson

#ad1b1e
Notes

Resolute Castor Crimson (#AD1B1E) 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 (359°, 73%, 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 cyan. For something softer, pull in its analogous neighbors on either side of the wheel.

HEX
#ad1b1e
RGB
rgb(173, 27, 30)
HSL
hsl(359, 73%, 39%)
HWB
hwb(359 11% 32%)
OKLCH
oklch(48.2% 0.180 26.6)
HSV
hsv(359, 84%, 68%)
LAB
lab(37.42% 56.15 37.85)
LCH
lch(37.42% 67.72 33.99)
CMYK
cmyk(0%, 84%, 83%, 32%)

Etymology

Resolute
adjective

From the Latin resolutus, unwavering — used as a color modifier in literary contexts for hues that read as committed and unmoving. Resolute blue, resolute green: the saturation is full, the hue holds its position without shifting under different light. Sits in the bold-bucket center alongside strong and true, with slightly more focus on stability than presence.

Castor
modifier

Greek Κάστωρ, Gemini-twin-and-horseman. As a color modifier, castor implies a Gemini-twin-and-mortal-brother quality, the visual register of Gemini-Castor-and-Pollux-twin hand-Gemini-twin-and-mortal-brother Gemini-Castor-and-Pollux-twin-and-Argonaut castor-and-Gemini-twin-and-mortal-brother surfaces under Gemini-Castor-and-Pollux-twin-and-Argonaut spring-Gemini-and-Bortle-1-sky stellar-twin-light. Sits at the modifier-and-cosmic end of the grid, parallel to pollux and spica 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.

#ad1b1e
Original
#4c441c
Protanopia
#6f6316
Deuteranopia
#bf001f
Tritanopia
#3a3a3a
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
7.11:1
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
2.95:1

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