Glowing Spirulina
Glowing Spirulina (#19B44D) is a true green with a vibrant character. It holds its own as a focal accent, carrying visual weight without tipping into neon territory. Its HSL profile (140°, 76%, 40%) places it in the highly saturated band at a mid 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 magenta. For something softer, pull in its analogous neighbors on either side of the wheel.
Etymology
The progressive participle of glow, to emit light — used as a color word since the medieval period for hues that read as if they were luminous from within. Glowing amber, glowing rose: the implication is moderate saturation combined with the optical impression of internal light. Sits in the bright-bucket alongside radiant.
Arthrospira platensis, the cyanobacterium harvested from alkaline lakes since the time of the Aztecs and now sold globally as a nutritional supplement and natural food coloring. The color refers to fresh-dried spirulina powder in a small bowl: a saturated, slightly cool deep blue-green with the matte finish of dehydrated cyanobacterial cells. Cooler than algae.
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.
This color is chromatic enough that authoring it as P3 native (instead of clamping to sRGB) gives a perceptibly more saturated render on wide-gamut displays — modern Macs, iPhones, iPads, and most recent OLED laptops.