Spectral Sill Chartreuse
Spectral Sill Chartreuse (#9AD86A) is a true lime 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 (94°, 59%, 63%) 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.
Etymology
Latin spectrum, appearance — adjectival suffix -al. As a color modifier, spectral implies a saturated-and-rainbow-decomposed-and-pure quality, the bright color of Newton-prism sunlight-decomposed seven-color spectrum band. Sits at the bright-and-pure end of the grid, parallel to prismatic and pure in usage.
Old English syll, threshold-beam. As a color modifier, sill implies a horizontal-bottom-of-window-or-door quality, the visual register of English-cottage-and-farmhouse hand-cut horizontal-window-and-door bottom-edge sill-and-threshold architectural surfaces under English-cottage-and-farmhouse sill-edge light. Sits at the modifier-and-architecture end of the grid, parallel to lintel and truss in usage.
The yellow-green French liqueur made by Carthusian monks at the Grande Chartreuse monastery since 1737, from a recipe of 130 herbs known to only two living monks at any time. The color is the base spirit chartreuse jaune in a glass: a saturated, slightly green yellow that's brighter than lemon and warmer than lime. The liqueur gave the color its name, not the other way around.
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 exploreHarmonies
Accessibility
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.
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.
Wide gamut
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.
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.