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Calm Polar

#51e5fc
Notes

Calm Polar (#51E5FC) 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 (188°, 97%, 65%) 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
#51e5fc
RGB
rgb(81, 229, 252)
HSL
hsl(188, 97%, 65%)
HWB
hwb(188 32% 1%)
OKLCH
oklch(85.3% 0.126 209.8)
HSV
hsv(188, 68%, 99%)
LAB
lab(84.39% -31.85 -22.62)
LCH
lch(84.39% 39.06 215.38)
CMYK
cmyk(68%, 9%, 0%, 1%)

Etymology

Calm
adjective

Latin calma, heat of the day — paradoxically drifted in Italian to mean stillness. Used as a color modifier since the seventeenth century for hues that read as untroubled. Calm blue, calm gray: moderate saturation combined with optical quiet. Sits at the crisp-bucket near quiet and steady.

Polar
noun

Of the polar — the ice caps and the meltwater seas at the high latitudes. The color refers to polar sea ice on a clear day at the height of summer melt: a soft, slightly green-shifted very pale blue with the optical brightness of bubble-rich ice. Lighter than glacier, cooler than frost, with the climatological weight of a region whose color is rapidly disappearing.

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.

#51e5fc
Original
#d1ddfd
Protanopia
#b9cbfc
Deuteranopia
#00efec
Tritanopia
#c7c7c7
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
1.50:1
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
13.96:1

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Canvas