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Refulgent Ergo Eucalyptus

#66ba6f
Notes

Refulgent Ergo Eucalyptus (#66BA6F) is a true green 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 (126°, 38%, 56%) 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 violet. For something softer, pull in its analogous neighbors on either side of the wheel.

HEX
#66ba6f
RGB
rgb(102, 186, 111)
HSL
hsl(126, 38%, 56%)
HWB
hwb(126 40% 27%)
OKLCH
oklch(71.7% 0.135 146.3)
P3
color(display-p3 0.4805 0.7214 0.4644)
HSV
hsv(126, 45%, 73%)
LAB
lab(68.82% -41.40 30.29)
LCH
lch(68.82% 51.29 143.81)
CMYK
cmyk(45%, 0%, 40%, 27%)

Etymology

Refulgent
adjective

Latin refulgēns, shining-back — present-participle of refulgere, sharing root with fulgor (lightning). As a color modifier, refulgent implies a saturated-and-reflective-shining quality, the bright color of polished-bronze-and-armor reflective-surface mid-day-sun reflection. Sits at the bright-and-saturated end of the grid, parallel to effulgent and resplendent in usage.

Ergo
modifier

Latin ergo, therefore-or-thus. As a color modifier, ergo implies a Latin-logical-and-cogito-ergo-sum quality, the visual register of Cartesian-cogito-ergo-sum hand-Latin-logical-and-cogito-ergo-sum Cartesian-cogito-ergo-sum-and-Scholastic-syllogism ergo-and-Latin-logical-and-cogito-ergo-sum surfaces under Cartesian-cogito-ergo-sum-and-Scholastic-syllogism Sorbonne-Scholastic-and-Cartesian-meditation logical-deduction-light. Sits at the modifier-and-Latin end of the grid, parallel to ipse and opus in usage.

Eucalyptus
noun

The genus Eucalyptus, the gum trees that dominate the Australian forest canopy and have been planted across the world for fast-growth timber and the menthol-camphor oil. The color refers to mature eucalyptus leaves with their pale waxy bloom: a soft, slightly muted blue-green with the matte finish of cuticle that reflects more light than typical foliage. Cooler than sage, warmer than mint.

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.

#66ba6f
Original
#bcad6a
Protanopia
#b0a574
Deuteranopia
#59b6a7
Tritanopia
#a3a3a3
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
2.38:1
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
8.82:1

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
##66BA6F
Display P3
Display P3
color(display-p3 0.4805 0.7214 0.4644)
P3 has subtle headroomOKLCH chroma 0.135

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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