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Even Cataract

#51bbe7
Notes

Even Cataract (#51BBE7) 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 (198°, 76%, 61%) 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 orange. For something softer, pull in its analogous neighbors on either side of the wheel.

HEX
#51bbe7
RGB
rgb(81, 187, 231)
HSL
hsl(198, 76%, 61%)
HWB
hwb(198 32% 9%)
OKLCH
oklch(74.8% 0.115 228.7)
P3
color(display-p3 0.4313 0.7242 0.8886)
HSV
hsv(198, 65%, 91%)
LAB
lab(71.59% -17.20 -30.96)
LCH
lch(71.59% 35.41 240.94)
CMYK
cmyk(65%, 19%, 0%, 9%)

Etymology

Even
adjective

Old English efen, flat, equal — used as a color modifier since the medieval period for hues that read as uniformly distributed across a surface. Even gray, even tan: the implication is moderate saturation combined with optical uniformity. Sits at the crisp-bucket center alongside steady and balanced.

Cataract
noun

A large waterfall with significant volume — particularly the Cataracts of the Nile and the Iguaçu Cataract of South America. Cataract color refers to the deep blue-white of high-volume falling water at Iguaçu: a saturated, slightly cool deep blue-white with the optical brightness of micron-scale air-water mixing.

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.

#51bbe7
Original
#a4b8e9
Protanopia
#8fa9e6
Deuteranopia
#00c7c9
Tritanopia
#a8a8a8
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
2.18:1
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
9.61:1

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
##51BBE7
Display P3
Display P3
color(display-p3 0.4313 0.7242 0.8886)
P3 has subtle headroomOKLCH chroma 0.115

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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