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Caliginous Trafalgar

#0a2166
Notes

Caliginous Trafalgar (#0A2166) 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 (225°, 82%, 22%) 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 amber. For something softer, pull in its analogous neighbors on either side of the wheel.

HEX
#0a2166
RGB
rgb(10, 33, 102)
HSL
hsl(225, 82%, 22%)
HWB
hwb(225 4% 60%)
OKLCH
oklch(28.4% 0.124 264.9)
P3
color(display-p3 0.0629 0.1274 0.3843)
HSV
hsv(225, 90%, 40%)
LAB
lab(16.06% 20.98 -42.73)
LCH
lch(16.06% 47.61 296.15)
CMYK
cmyk(90%, 68%, 0%, 60%)

Etymology

Caliginous
adjective

Latin cālīginōsus, misty / dark — derived from cālīgō (mist, gloom). As a color modifier, caliginous implies an obscured, dimmed, slightly-cool-shifted quality where the hue is veiled by darkness or atmospheric fog. Sits at the deep-and-veiled end of the grid, between murky and tenebrous in usage.

Trafalgar
noun

The Cape Trafalgar headland off southern Spain — site of the 1805 Battle of Trafalgar (Nelson's decisive naval victory over Napoleon's fleet). Trafalgar color refers to the deep blue of HMS Victory's preserved hull paint at Portsmouth: a saturated, slightly cool deep blue with the matte finish of period-correct marine paint.

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.

#0a2166
Original
#002c68
Protanopia
#002465
Deuteranopia
#003340
Tritanopia
#212121
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
14.76:1
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
1.42:1

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
##0A2166
Display P3
Display P3
color(display-p3 0.0629 0.1274 0.3843)
P3 has subtle headroomOKLCH chroma 0.124

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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