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Plunged Riebeckite

#0f378e
Notes

Plunged Riebeckite (#0F378E) 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 (221°, 81%, 31%) 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
#0f378e
RGB
rgb(15, 55, 142)
HSL
hsl(221, 81%, 31%)
HWB
hwb(221 6% 44%)
OKLCH
oklch(37.1% 0.151 262.8)
HSV
hsv(221, 89%, 56%)
LAB
lab(26.12% 22.34 -51.74)
LCH
lch(26.12% 56.35 293.36)
CMYK
cmyk(89%, 61%, 0%, 44%)

Etymology

Plunged
adjective

Old French plonger, to plunge via Latin plumbicāre (to weight with lead) — past-participle of plunge. As a color modifier, plunged implies the deep-and-suddenly-deepened quality of a hue forced into darkness. Sits at the deep-and-rapid-shift end of the grid, parallel to submerged with kinetic register.

Riebeckite
noun

A sodium-iron amphibole — the source of crocidolite (blue asbestos) and the chatoyant inclusions in hawk's-eye quartz. Mined principally in South Africa and Australia. The color refers to a freshly cleaved riebeckite specimen: a deep, slightly cool dark blue-gray with the slight metallic shine of amphibole.

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.

#0f378e
Original
#004491
Protanopia
#00388c
Deuteranopia
#004d5d
Tritanopia
#353535
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
10.73:1
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
1.96:1

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