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Spectral Yellowtail

#acb621
Notes

Spectral Yellowtail (#ACB621) is a true yellow with a vibrant character. It holds its own as a focal accent, carrying visual weight without tipping into neon territory. Its HSL profile (64°, 69%, 42%) places it in the balanced band at a mid lightness. It works across type, buttons, and borders, saturated enough to feel deliberate but balanced enough to not fight the rest of the palette. For a confident two-color system, pair it with its complementary blue. For something softer, pull in its analogous neighbors on either side of the wheel.

HEX
#acb621
RGB
rgb(172, 182, 33)
HSL
hsl(64, 69%, 42%)
HWB
hwb(64 13% 29%)
OKLCH
oklch(74.4% 0.158 113.7)
P3
color(display-p3 0.6817 0.7125 0.2595)
HSV
hsv(64, 82%, 71%)
LAB
lab(71.10% -20.45 67.05)
LCH
lch(71.10% 70.10 106.96)
CMYK
cmyk(5%, 0%, 82%, 29%)

Etymology

Spectral
adjective

Latin spectrum, appearance — adjectival suffix -al. As a color modifier, spectral implies a saturated-and-rainbow-decomposed-and-pure quality, the bright color of Newton-prism sunlight-decomposed seven-color spectrum band. Sits at the bright-and-pure end of the grid, parallel to prismatic and pure in usage.

Yellowtail
noun

Seriola lalandi, the Pacific yellowtail amberjack — a sport fish prized in Japanese sushi cuisine as hamachi. The color refers to the yellow stripe along the lateral line: a saturated, slightly cool yellow with the matte finish of carotenoid-pigmented fish skin. Cooler than goldfinch.

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.

#acb621
Original
#c4ad00
Protanopia
#c4af30
Deuteranopia
#b8ab9b
Tritanopia
#a9a9a9
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).
Failon White
2.22:1
The quick brown foxSample body text at normal size. The wcag minimum for body contrast is 4.5:1 (AA) or 7:1 (AAA).
AAAon Black
9.47:1

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
##ACB621
Display P3
Display P3
color(display-p3 0.6817 0.7125 0.2595)
P3 has subtle headroomOKLCH chroma 0.158

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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