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Authoritative Romaine

#638b1d
Notes

Authoritative Romaine (#638B1D) is a deep lime 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 (82°, 65%, 33%) places it in the balanced band at a dark lightness. It works well as a headline, icon, or deep background in an otherwise light layout, pairing cleanly with cream, bone, and warm neutrals. 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
#638b1d
RGB
rgb(99, 139, 29)
HSL
hsl(82, 65%, 33%)
HWB
hwb(82 11% 45%)
OKLCH
oklch(58.6% 0.141 128.2)
P3
color(display-p3 0.4215 0.5408 0.1965)
HSV
hsv(82, 79%, 55%)
LAB
lab(53.17% -30.39 50.19)
LCH
lch(53.17% 58.67 121.19)
CMYK
cmyk(29%, 0%, 79%, 45%)

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.

Romaine
noun

Lactuca sativa var. longifolia, the upright lettuce variety whose tall green-and-white heads are essential to Caesar salad. Named for Rome, where the Romans cultivated it for European salad tradition. The color refers to a fresh romaine leaf: a soft, slightly cool yellow-green with the satin finish of dewy lettuce.

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.

#638b1d
Original
#928100
Protanopia
#8d7e28
Deuteranopia
#678477
Tritanopia
#7b7b7b
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
4.01:1
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
5.24:1

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
##638B1D
Display P3
Display P3
color(display-p3 0.4215 0.5408 0.1965)
P3 has subtle headroomOKLCH chroma 0.141

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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