Fluorescent Apse Lime
Fluorescent Apse Lime (#9EF186) is a soft 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 (107°, 79%, 74%) places it in the highly saturated band at a light 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.
Etymology
Latin fluēre, to flow — adjectival suffix -escent. As a color modifier, fluorescent implies a saturated-and-UV-stimulated-glow quality, the bright color of fluorite-and-ZnS mineral-pigment fluorescent-lamp emission. Sits at the bright-and-cool end of the grid, parallel to phosphorescent and neon in usage.
Latin absis, vault / arch-recess. As a color modifier, apse implies a semicircular-vaulted-altar-end quality, the visual register of Romanesque-and-Byzantine-cathedral hand-laid mosaic-and-fresco-decorated semicircular altar-end vaulted-apse architectural surfaces under candle-and-incense apse light. Sits at the modifier-and-architecture end of the grid, parallel to nave and aisle in usage.
Citrus aurantiifolia and its key-lime cousin — small, intensely sour green citrus carried by Arab traders from Southeast Asia to the Mediterranean by the eleventh century, then to the Caribbean with Columbus. The color refers to the skin of a fully ripe Persian lime: a saturated, slightly yellow-shifted green with the matte finish of citrus rind. Cooler than chartreuse, sharper than sage, with the same chlorophyll the fruit loses if left to ripen to yellow.
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.