colors
Back to gallery

Effervescent Demantoid

#66a822
Notes

Effervescent Demantoid (#66A822) is a true lime with a vibrant character. It holds its own as a focal accent, carrying visual weight without tipping into neon territory. Its HSL profile (90°, 66%, 40%) 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 indigo. For something softer, pull in its analogous neighbors on either side of the wheel.

HEX
#66a822
RGB
rgb(102, 168, 34)
HSL
hsl(90, 66%, 40%)
HWB
hwb(90 13% 34%)
OKLCH
oklch(66.2% 0.173 133.0)
HSV
hsv(90, 80%, 66%)
LAB
lab(62.46% -41.94 57.34)
LCH
lch(62.46% 71.04 126.18)
CMYK
cmyk(39%, 0%, 80%, 34%)

Etymology

Effervescent
adjective

Latin effervēscēns, boiling-out — present-participle of effervesce, sharing root with fervere (to boil). As a color modifier, effervescent implies a saturated-and-bubbling-and-active quality, the bright color of Champagne-and-Prosecco effervescent-wine carbonation-bubble-light reflection. Sits at the bright-and-effervescent end of the grid, parallel to fizzy and sparkling in usage.

Demantoid
noun

A green variety of andradite garnet — known for its high dispersion (more than diamond) and prized in late-Tsarist-era Russian jewelry. Mined principally in the Russian Urals, Namibia, and Madagascar. The color refers to a faceted Russian demantoid: a saturated, slightly cool deep green with the gem's signature internal fire.

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.

#66a822
Original
#af9a00
Protanopia
#a69531
Deuteranopia
#66a18f
Tritanopia
#909090
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
2.92:1
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
7.19:1

Related Colors

Canvas