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Suffocating Aster

#18154a
Notes

Suffocating Aster (#18154A) is a deep blue with a cool character. It leans cool, sitting on the blue, green, and violet side of the wheel. Quiet and dependable, a fit for product UI and data visualization. Its HSL profile (243°, 56%, 19%) 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 yellow. For something softer, pull in its analogous neighbors on either side of the wheel.

HEX
#18154a
RGB
rgb(24, 21, 74)
HSL
hsl(243, 56%, 19%)
HWB
hwb(243 8% 71%)
OKLCH
oklch(23.9% 0.095 278.9)
P3
color(display-p3 0.0921 0.0828 0.2785)
HSV
hsv(243, 72%, 29%)
LAB
lab(10.74% 19.98 -32.52)
LCH
lch(10.74% 38.17 301.56)
CMYK
cmyk(68%, 72%, 0%, 71%)

Etymology

Suffocating
adjective

Latin suffocāre, to choke — present-participle of suffocate. As a color modifier, suffocating implies a deep-and-overwhelming-and-pressing quality where the hue overwhelms the eye's capacity to discern surface detail. Sits at the deep-and-overwhelming end of the grid, parallel to smothering with breath-restricting register.

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.

#18154a
Original
#001f4c
Protanopia
#001b49
Deuteranopia
#00222d
Tritanopia
#191919
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
16.87:1
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
1.24:1

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
##18154A
Display P3
Display P3
color(display-p3 0.0921 0.0828 0.2785)
P3 has subtle headroomOKLCH chroma 0.095

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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