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Menacing Cobalt

#0b3f8b
Notes

Menacing Cobalt (#0B3F8B) is a deep azure 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 (216°, 85%, 29%) 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
#0b3f8b
RGB
rgb(11, 63, 139)
HSL
hsl(216, 85%, 29%)
HWB
hwb(216 4% 45%)
OKLCH
oklch(38.5% 0.137 259.2)
P3
color(display-p3 0.1096 0.2431 0.5258)
HSV
hsv(216, 92%, 55%)
LAB
lab(28.09% 15.22 -46.68)
LCH
lch(28.09% 49.09 288.06)
CMYK
cmyk(92%, 55%, 0%, 45%)

Etymology

Menacing
adjective

Latin minārī, to threaten — present-participle of menace, sharing root with minatory. As a color modifier, menacing implies a deep-and-threatening-and-imposing quality, the dark cool-gray of looming storm-cloud-and-imposing-cliff visual-presence. Sits at the deep-and-threatening end of the grid, parallel to ominous and foreboding in tone.

Cobalt
noun

Element Co, atomic number 27 — German Kobold, goblin, named by miners who found the metal interfered with smelting silver ore. Cobalt blue is the cobalt-aluminate pigment introduced by Louis Jacques Thénard in 1802: a saturated, slightly green-shifted deep blue with the matte finish of mineral pigment in oil. Cooler than ultramarine, warmer than prussian, with the painter's weight of a pigment used by Renoir, Van Gogh, and Cézanne.

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.

#0b3f8b
Original
#00488e
Protanopia
#003d8a
Deuteranopia
#00525e
Tritanopia
#393939
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
10.01:1
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
2.10:1

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
##0B3F8B
Display P3
Display P3
color(display-p3 0.1096 0.2431 0.5258)
P3 has subtle headroomOKLCH chroma 0.137

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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