Fluorescent Blue sits in the cyan / teal family, with the hex code #15F4EE mapping to rgb(21, 244, 238) in RGB and hsl(178.4, 91%, 52%) in HSL. In OKLCH it carries 87% perceptual lightness and 0.148 chroma — a moderately saturated, light reading that behaves well as a background, surface or supporting tone in modern interfaces. Cyan sits exactly where blue meets green and inherits the calm of both. It reads as clean, modern and slightly futuristic, which is why so many cloud, AI and medical brands gravitate to it — it feels technical without feeling cold.
Cyan sits exactly where blue meets green and inherits the calm of both. It reads as clean, modern and slightly futuristic, which is why so many cloud, AI and medical brands gravitate to it — it feels technical without feeling cold.
Cyan washes out against bright backgrounds — it almost always needs at least 30% lightness reduction to clear AA on white. Watch saturation in dark mode too, where neon cyans bloom.
#15F4EErgb(21, 244, 238)hsl(178.4, 91%, 52%)hsv(178.4, 91.4%, 95.7%)lch(87.1% 51.07 192.95)oklch(87.45% 0.1485 191.58)lab(87.1% -49.77 -11.44):root {
--color: #15f4ee;
--color-rgb: rgb(21, 244, 238);
--color-hsl: hsl(178.4, 91%, 52%);
--color-oklch: oklch(87.45% 0.1485 191.58);
}How fluorescent blue performs as foreground text on common surfaces, scored with WCAG 2.1.
Tints are produced by mixing fluorescent blue with progressively more white.
Shades are produced by mixing fluorescent blue with progressively more black.
Tones are produced by mixing fluorescent blue with progressively more gray, lowering chroma while keeping lightness.