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Spectral Cascade

#39ece4
Notes

Spectral Cascade (#39ECE4) is a true cyan with a vibrant character. It holds its own as a focal accent, carrying visual weight without tipping into neon territory. Its HSL profile (177°, 82%, 57%) 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 red. For something softer, pull in its analogous neighbors on either side of the wheel.

HEX
#39ece4
RGB
rgb(57, 236, 228)
HSL
hsl(177, 82%, 57%)
HWB
hwb(177 22% 7%)
OKLCH
oklch(85.6% 0.137 190.3)
P3
color(display-p3 0.4644 0.9125 0.8900)
HSV
hsv(177, 76%, 93%)
LAB
lab(85.23% -44.68 -8.75)
LCH
lch(85.23% 45.53 191.09)
CMYK
cmyk(76%, 0%, 3%, 7%)

Etymology

Spectral
adjective

Latin spectrum, appearance — adjectival suffix -al. As a color modifier, spectral implies a saturated-and-rainbow-decomposed-and-pure quality, the bright color of Newton-prism sunlight-decomposed seven-color spectrum band. Sits at the bright-and-pure end of the grid, parallel to prismatic and pure in usage.

Cascade
noun

A waterfall of moderate size — particularly the Cascade Range of waterfalls along the Pacific Northwest's Columbia River Gorge. Cascade color refers to the white-and-blue of falling water at Multnomah Falls: a soft, slightly cool pale blue-white with the optical complexity of mist-and-water in motion.

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 explore

Harmonies

Accessibility

Color-vision simulation

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.

#39ece4
Original
#dedfe4
Protanopia
#c5cde5
Deuteranopia
#00f2e9
Tritanopia
#c5c5c5
Achromatopsia
WCAG contrast

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.

The quick brown foxSample body text at normal size. The wcag minimum for body contrast is 4.5:1 (AA) or 7:1 (AAA).
Failon White
1.47:1
The quick brown foxSample body text at normal size. The wcag minimum for body contrast is 4.5:1 (AA) or 7:1 (AAA).
AAAon Black
14.29:1

Wide gamut

Display P3 representation

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.

sRGB hex
sRGB hex
##39ECE4
Display P3
Display P3
color(display-p3 0.4644 0.9125 0.8900)
P3 has subtle headroomOKLCH chroma 0.137

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.

Related Colors

Canvas