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Menacing Observatory

#0d378b
Notes

Menacing Observatory (#0D378B) 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 (220°, 83%, 30%) 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
#0d378b
RGB
rgb(13, 55, 139)
HSL
hsl(220, 83%, 30%)
HWB
hwb(220 5% 45%)
OKLCH
oklch(36.8% 0.147 262.1)
HSV
hsv(220, 91%, 55%)
LAB
lab(25.81% 20.97 -50.39)
LCH
lch(25.81% 54.58 292.60)
CMYK
cmyk(91%, 60%, 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.

Observatory
noun

An astronomical research facility — particularly the deep-blue interior paint of optical observatories like Mount Wilson, Palomar, and Mauna Kea. The deep blue minimizes stray-light reflection inside the dome. The color refers to the painted interior of a research-grade optical observatory: a saturated, slightly cool very deep blue with the matte finish of low-reflectance enamel.

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

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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.

#0d378b
Original
#00438e
Protanopia
#003889
Deuteranopia
#004d5b
Tritanopia
#343434
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
10.84:1
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
1.94:1

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