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Crepuscular Ametrine

#640a56
Notes

Crepuscular Ametrine (#640A56) is a deep violet 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 (309°, 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 green. For something softer, pull in its analogous neighbors on either side of the wheel.

HEX
#640a56
RGB
rgb(100, 10, 86)
HSL
hsl(309, 82%, 22%)
HWB
hwb(309 4% 61%)
OKLCH
oklch(35.0% 0.145 336.0)
HSV
hsv(309, 90%, 39%)
LAB
lab(22.30% 44.94 -21.49)
LCH
lch(22.30% 49.82 334.44)
CMYK
cmyk(0%, 90%, 14%, 61%)

Etymology

Crepuscular
adjective

Latin crepusculāris, of twilight — derived from crepusculum (twilight). As a color modifier, crepuscular implies the deep blue-violet darkness of civil-twilight period between sunset and nightfall. Sits at the deep-and-cool end of the grid, where the hue carries the Belt of Venus atmospheric-scattering quality of clear-sky horizon at dusk.

Ametrine
noun

Naturally bicolored amethyst-citrine zoned quartz mined principally at the Anahí mine in eastern Bolivia. The deep-violet amethyst portion contrasts with the golden citrine zone in a single crystal. Ametrine color refers to the deep-violet amethyst zone of a polished Anahí-mine ametrine cabochon: a saturated, slightly cool deep violet with the glassy finish of iron-and-aluminum-substituted quartz under reflected light.

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.

#640a56
Original
#0c2d58
Protanopia
#2f3a54
Deuteranopia
#6a1331
Tritanopia
#232323
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
12.21:1
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
1.72:1

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