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Glowing Oolong

#42effc
Notes

Glowing Oolong (#42EFFC) is a true cyan with a neon character. It sits at the high-saturation edge of its family. Use it sparingly, as signage, accent, or highlight against darker surfaces. Its HSL profile (184°, 97%, 62%) 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
#42effc
RGB
rgb(66, 239, 252)
HSL
hsl(184, 97%, 62%)
HWB
hwb(184 26% 1%)
OKLCH
oklch(87.3% 0.136 202.6)
P3
color(display-p3 0.4823 0.9243 0.9776)
HSV
hsv(184, 74%, 99%)
LAB
lab(86.95% -38.33 -18.76)
LCH
lch(86.95% 42.68 206.08)
CMYK
cmyk(74%, 5%, 0%, 1%)

Etymology

Glowing
adjective

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.

Oolong
noun

The partially-oxidized Chinese tea — qīng-chá (cyan tea) — with the deep blue-green liquor distinct from green tea (lower oxidation) and black tea (higher oxidation). The color refers to fresh-brewed Tieguanyin oolong: a saturated, slightly cool deep blue-green with the optical depth of partially-fermented tea liquor.

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.

#42effc
Original
#dce5fd
Protanopia
#c2d2fd
Deuteranopia
#00f8f3
Tritanopia
#cbcbcb
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
1.40:1
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
14.98:1

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
##42EFFC
Display P3
Display P3
color(display-p3 0.4823 0.9243 0.9776)
P3 has subtle headroomOKLCH chroma 0.136

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.

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