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Bright Cerulean

#28eefb
Notes

Bright Cerulean (#28EEFB) 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°, 96%, 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
#28eefb
RGB
rgb(40, 238, 251)
HSL
hsl(184, 96%, 57%)
HWB
hwb(184 16% 2%)
OKLCH
oklch(86.6% 0.142 202.2)
HSV
hsv(184, 84%, 98%)
LAB
lab(86.29% -40.36 -19.28)
LCH
lch(86.29% 44.73 205.53)
CMYK
cmyk(84%, 5%, 0%, 2%)

Etymology

Bright
adjective

Old English beorht, shining, luminous — cognate with the German Bracht, splendor. Applied to color since at least the medieval period for hues that read as luminous: not just light in value but optically active, as if scattering more light back than a dimmer color of the same lightness would. Sits at the bright-bucket center alongside vivid and brilliant.

Cerulean
noun

From the Latin caeruleum, originally referring to dark blue paint pigment of the Roman world, then via French céruléen into English. As a modern art-supply name, cerulean blue is the cobalt-tin oxide pigment introduced in 1805. The color refers to a clean, slightly green-shifted blue with the matte finish of mineral pigment in linseed oil: lighter than cobalt, deeper than aqua, with the painter's weight of a word for sky.

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.

#28eefb
Original
#dbe3fc
Protanopia
#bfcffc
Deuteranopia
#00f8f2
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
1.43:1
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
14.71:1

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