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Cool Aster

#643874
Notes

Cool Aster (#643874) is a deep violet 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 (284°, 35%, 34%) 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 green. For something softer, pull in its analogous neighbors on either side of the wheel.

HEX
#643874
RGB
rgb(100, 56, 116)
HSL
hsl(284, 35%, 34%)
HWB
hwb(284 22% 55%)
OKLCH
oklch(42.1% 0.108 316.4)
P3
color(display-p3 0.3685 0.2279 0.4418)
HSV
hsv(284, 52%, 45%)
LAB
lab(31.34% 30.56 -26.73)
LCH
lch(31.34% 40.60 318.83)
CMYK
cmyk(14%, 52%, 0%, 55%)

Etymology

Cool
adjective

Old English cōl, of low temperature — used as a color modifier as the complement to warm. Cool gray, cool blue: the optical impression of a slight blue-green shift, even within otherwise warm or neutral hues. Sits across the crisp, hushed, pale, and neutral buckets.

Aster
noun

The genus Aster — Greek for star — composite-family perennials whose blue-violet daisy-like flowers fill gardens in September and October when most other bloomers have finished. The color refers to a fresh New England aster (Symphyotrichum novae-angliae): a saturated, slightly violet-shifted blue with the matte finish of multi-rayed composite flowers. Cooler than veronica, warmer than larkspur, with the late-season weight of a flower that closes the perennial year.

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.

#643874
Original
#2c4776
Protanopia
#394b72
Deuteranopia
#634150
Tritanopia
#464646
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
8.90:1
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
2.36:1

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
##643874
Display P3
Display P3
color(display-p3 0.3685 0.2279 0.4418)
P3 has subtle headroomOKLCH chroma 0.108

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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