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Cavernous Crimson

#681505
Notes

Cavernous Crimson (#681505) 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 (10°, 91%, 21%) 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 cyan. For something softer, pull in its analogous neighbors on either side of the wheel.

HEX
#681505
RGB
rgb(104, 21, 5)
HSL
hsl(10, 91%, 21%)
HWB
hwb(10 2% 59%)
OKLCH
oklch(34.1% 0.119 32.9)
P3
color(display-p3 0.3737 0.1112 0.0538)
HSV
hsv(10, 95%, 41%)
LAB
lab(21.91% 35.73 30.61)
LCH
lch(21.91% 47.05 40.59)
CMYK
cmyk(0%, 80%, 95%, 59%)

Etymology

Cavernous
adjective

An adjectival form of cavern, used principally for the deep darkness of large enclosed spaces. As a color modifier, cavernous implies the slightly cool deep blacks of a Lascaux-style cave or a basilica crypt — darkness with the optical complexity of a space larger than any single light source can fill. Sits in the deep-and-spatial end of the grid.

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

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.

#681505
Original
#2f2902
Protanopia
#433b01
Deuteranopia
#730013
Tritanopia
#252525
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
12.37:1
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
1.70:1

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
##681505
Display P3
Display P3
color(display-p3 0.3737 0.1112 0.0538)
P3 has subtle headroomOKLCH chroma 0.119

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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