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Open Horn Denim

#51659d
Notes

Open Horn Denim (#51659D) is a true azure with an earthy character. It leans grounded and natural, the kind of color that plays well with wood, clay, linen, and warm neutrals. Its HSL profile (224°, 32%, 47%) 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 amber. For something softer, pull in its analogous neighbors on either side of the wheel.

HEX
#51659d
RGB
rgb(81, 101, 157)
HSL
hsl(224, 32%, 47%)
HWB
hwb(224 32% 38%)
OKLCH
oklch(51.6% 0.092 268.2)
P3
color(display-p3 0.3332 0.3938 0.5994)
HSV
hsv(224, 48%, 62%)
LAB
lab(43.49% 8.44 -32.78)
LCH
lch(43.49% 33.85 284.45)
CMYK
cmyk(48%, 36%, 0%, 38%)

Etymology

Open
adjective

Old English open, unobstructed — used as a color modifier since the eighteenth century for hues that read as airy or uncrowded. Open blue, open green: moderate saturation combined with optical spaciousness, the slight visual breath of a hue that doesn't crowd the surface it covers. Sits at the crisp-bucket center alongside clear.

Horn
modifier

Old English horn, horn. As a color modifier, horn implies a translucent-keratin quality, the visual register of cattle-horn-and-deer-antler hand-shaped-and-polished translucent-keratin button-and-comb-and-knife-handle horn-and-antler surfaces under translucent-horn-and-antler hand-polished light. Sits at the modifier-and-texture end of the grid, parallel to bone and pith in usage.

Denim
noun

The diagonal-twill cotton fabric originally woven in Nîmes, France — serge de Nîmes, contracted to denim — and dyed with indigo since at least the eighteenth century. The color refers to a worn but un-faded pair of raw denim jeans: a saturated, slightly muted blue with the matte finish of cotton fiber that has absorbed dye through generations of weft and warp. Cooler than royal, warmer than navy.

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.

#51659d
Original
#506a9f
Protanopia
#48649c
Deuteranopia
#337179
Tritanopia
#656565
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).
AAon White
5.68:1
The quick brown foxSample body text at normal size. The wcag minimum for body contrast is 4.5:1 (AA) or 7:1 (AAA).
AA Largeon Black
3.70:1

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
##51659D
Display P3
Display P3
color(display-p3 0.3332 0.3938 0.5994)
P3 has subtle headroomOKLCH chroma 0.092

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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