Mighty Fern
Mighty Fern (#359B00) 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 (99°, 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 indigo. For something softer, pull in its analogous neighbors on either side of the wheel.
Etymology
Old English mihtig, strong — adjectival suffix -y, sharing root with German mächtig. As a color modifier, mighty implies a saturated-and-strong-presence quality, where the hue commands visual attention through pure pigmentation strength. Sits at the bold-and-saturated end of the grid, parallel to forceful and commanding in tone.
The Polypodiopsida — vascular spore-bearing plants that dominated terrestrial flora during the Carboniferous, when their compressed bodies became most of the world's coal. The color refers to the upper surface of a healthy mid-summer fern frond: a saturated, slightly muted green with the matte finish of mature pinnae. Deeper than moss, cooler than chartreuse, with the patient persistence of a plant family three hundred million years old.
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.