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Authoritative Sumatra

#118029
Notes

Authoritative Sumatra (#118029) is a deep green with a jewel character. It carries the deep, saturated richness of a gemstone. Authoritative and slightly formal, it works well for type and heavy UI elements. Its HSL profile (133°, 77%, 28%) places it in the highly saturated band at a dark lightness. Best used in small doses, like logos, CTAs, focus rings, or highlight text, where its saturation becomes a feature rather than noise. For a confident two-color system, pair it with its complementary magenta. For something softer, pull in its analogous neighbors on either side of the wheel.

HEX
#118029
RGB
rgb(17, 128, 41)
HSL
hsl(133, 77%, 28%)
HWB
hwb(133 7% 50%)
OKLCH
oklch(52.4% 0.155 145.6)
HSV
hsv(133, 87%, 50%)
LAB
lab(46.60% -47.56 37.82)
LCH
lch(46.60% 60.76 141.51)
CMYK
cmyk(87%, 0%, 68%, 50%)

Etymology

Authoritative
adjective

Latin auctōritāt-, authority — adjectival suffix -ive. As a color modifier, authoritative implies a saturated-and-formal-imperative quality where the hue carries decisional weight and institutional credibility. Sits at the bold-and-authoritative end of the grid, parallel to commanding and magisterial in usage.

Sumatra
noun

The Indonesian island — home to the Sumatran orangutan, tiger, and rhinoceros — and the deep green of Sumatran rainforest and Coffea arabica coffee plantations. Sumatra color refers to a Sumatran highland coffee plantation: a saturated, slightly cool deep green with the matte finish of broad-leaved coffee shrubs.

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

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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.

#118029
Original
#82731e
Protanopia
#766b31
Deuteranopia
#007d6e
Tritanopia
#626262
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).
AAon White
5.07:1
The quick brown foxSample body text at normal size. The wcag minimum for body contrast is 4.5:1 (AA) or 7:1 (AAA).
AA Largeon Black
4.14:1

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