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Tenebrous Earth

#12174b
Notes

Tenebrous Earth (#12174B) is a deep blue 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 (235°, 61%, 18%) 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 yellow. For something softer, pull in its analogous neighbors on either side of the wheel.

HEX
#12174b
RGB
rgb(18, 23, 75)
HSL
hsl(235, 61%, 18%)
HWB
hwb(235 7% 71%)
OKLCH
oklch(23.9% 0.095 272.6)
P3
color(display-p3 0.0744 0.0896 0.2823)
HSV
hsv(235, 76%, 29%)
LAB
lab(10.92% 17.88 -32.94)
LCH
lch(10.92% 37.49 298.50)
CMYK
cmyk(76%, 69%, 0%, 71%)

Etymology

Tenebrous
adjective

Latin tenebrōsus, full of darkness — derived from tenebrae (the deepening shadows of evening prayer service). As a color modifier, tenebrous implies a literary-poetic register for deep-shadowed darkness, where the hue is overwhelmed by ambient gloom. Sits at the deep-and-cool end of the grid, near Stygian but with painterly-baroque connotations.

Earth
noun

The third planet from the Sun — and the saturated deep blue of Earth seen from space, the pale blue dot of Carl Sagan's Voyager-1 image. Earth color refers to the average reflectance of Earth seen from low orbit: a saturated, slightly cool deep blue with the optical complexity of ocean-and-cloud-and-atmosphere reflectance.

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.

#12174b
Original
#00204d
Protanopia
#001b4a
Deuteranopia
#00242e
Tritanopia
#1a1a1a
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
16.80:1
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
1.25:1

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
##12174B
Display P3
Display P3
color(display-p3 0.0744 0.0896 0.2823)
P3 has subtle headroomOKLCH chroma 0.095

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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