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Forthright Sumatra

#1b9900
Notes

Forthright Sumatra (#1B9900) 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 (109°, 100%, 30%) 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 violet. For something softer, pull in its analogous neighbors on either side of the wheel.

HEX
#1b9900
RGB
rgb(27, 153, 0)
HSL
hsl(109, 100%, 30%)
HWB
hwb(109 0% 40%)
OKLCH
oklch(59.4% 0.198 141.5)
HSV
hsv(109, 100%, 60%)
LAB
lab(55.09% -56.68 57.10)
LCH
lch(55.09% 80.45 134.79)
CMYK
cmyk(82%, 0%, 100%, 40%)

Etymology

Forthright
adjective

Old English forð-riht, straight ahead, direct. Used as a color modifier in Anglo-Saxon-revival contexts for hues that read as honest and unguarded. Forthright red, forthright blue: the saturation is full, the hue is presented without ornamentation or qualification. Sits in the bold-bucket center alongside frank and direct.

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.

#1b9900
Original
#9d8900
Protanopia
#90801f
Deuteranopia
#009481
Tritanopia
#737373
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).
AA Largeon White
3.75:1
The quick brown foxSample body text at normal size. The wcag minimum for body contrast is 4.5:1 (AA) or 7:1 (AAA).
AAon Black
5.60:1

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