Cool Algae
Cool Algae (#9CF0AC) is a soft green with a pastel character. It reads calm and airy, with enough chroma to feel intentional rather than washed out. Its HSL profile (131°, 74%, 78%) places it in the balanced band at a light lightness. It works as a background wash, large-area fill, or soft illustration tone. Add a darker ink of the same hue when you need type over it. 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 cōl, of low temperature — used as a color modifier as the complement to warm. Cool gray, cool blue: the optical impression of a slight blue-green shift, even within otherwise warm or neutral hues. Sits across the crisp, hushed, pale, and neutral buckets.
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.