Knightly Algae
Knightly Algae (#198D42) 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 (141°, 70%, 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 magenta. For something softer, pull in its analogous neighbors on either side of the wheel.
Etymology
Old English cniht, young man / knight — adjectival suffix -ly. As a color modifier, knightly implies a saturated-and-chivalrous-and-medieval quality, the deep-rich color of medieval-English-and-French knight-and-squire armorial-bearings-and-livery tradition. Sits at the bold-and-chivalrous end of the grid, parallel to gallant and cavalier.
A vast collection of photosynthetic eukaryotes — green algae (Chlorophyta), kelps (Phaeophyceae), and dozens of other lineages — that gave rise to all land plants and still produce roughly half of Earth's oxygen. The color refers to a green algal bloom on a still pond: a saturated, slightly muted yellow-green with the matte chlorophyll finish of cellular density. Brighter than moss, cooler than spinach, with the geological weight of a kingdom three billion 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.
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.