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Ominous Cobalto

#284278
Notes

Ominous Cobalto (#284278) is a deep 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 (221°, 50%, 31%) 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 amber. For something softer, pull in its analogous neighbors on either side of the wheel.

HEX
#284278
RGB
rgb(40, 66, 120)
HSL
hsl(221, 50%, 31%)
HWB
hwb(221 16% 53%)
OKLCH
oklch(38.8% 0.097 263.2)
P3
color(display-p3 0.1797 0.2562 0.4557)
HSV
hsv(221, 67%, 47%)
LAB
lab(28.65% 8.95 -33.87)
LCH
lch(28.65% 35.03 284.80)
CMYK
cmyk(67%, 45%, 0%, 53%)

Etymology

Ominous
adjective

Latin ōminōsus, full of foreboding — derived from omen. As a color modifier, ominous implies a deep-and-threatening atmospheric-foreboding quality, the dark cool-gray of Goyaesque storm-laden sky. Sits at the deep-and-threatening end of the grid, parallel to foreboding and menacing in tone.

Cobalto
noun

The Italian word for cobalt — used for the saturated deep blue of cobalto-glaze on Tuscan and Venetian Renaissance ceramics. The color refers to a cobalto-glazed Tuscan piatto: a saturated, slightly cool deep blue with the high gloss of cobalt-glazed porcelain. The Italian cousin of cobalt.

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.

#284278
Original
#29477a
Protanopia
#1c4077
Deuteranopia
#004e57
Tritanopia
#404040
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
9.81:1
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
2.14:1

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
##284278
Display P3
Display P3
color(display-p3 0.1797 0.2562 0.4557)
P3 has subtle headroomOKLCH chroma 0.097

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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