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Sterile Bank Lagoon

#31c4e0
Notes

Sterile Bank Lagoon (#31C4E0) 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 (190°, 74%, 54%) places it in the balanced band at a mid lightness. It works across type, buttons, and borders, saturated enough to feel deliberate but balanced enough to not fight the rest of the palette. 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
#31c4e0
RGB
rgb(49, 196, 224)
HSL
hsl(190, 74%, 54%)
HWB
hwb(190 19% 12%)
OKLCH
oklch(75.8% 0.123 214.1)
P3
color(display-p3 0.3860 0.7578 0.8646)
HSV
hsv(190, 78%, 88%)
LAB
lab(73.23% -28.08 -24.71)
LCH
lch(73.23% 37.41 221.35)
CMYK
cmyk(78%, 12%, 0%, 12%)

Etymology

Sterile
adjective

Latin sterilis, barren / not-fertile — sharing root with Greek steiros (barren). As a color modifier, sterile implies a clear-and-medical-clean-and-stripped quality, the crisp color of operating-theater surgical-environment white-and-stainless-steel surfaces. Sits at the crisp-and-clean end of the grid, parallel to sanitary and hygienic in usage.

Bank
modifier

Old Norse bakki, raised ground beside river. As a color modifier, bank implies a riverside-rise-and-sediment quality, the visual register of Thames-Severn-and-Loire river-bank willow-shaded sediment-and-mudflat hand-walked path-side surfaces in slow-moving river-light. Sits at the modifier-and-place end of the grid, parallel to shore and bluff in usage.

Lagoon
noun

A shallow body of saltwater partially or fully enclosed by a barrier — coral atoll lagoons in the Pacific, Venice's Laguna Veneta, the Florida Keys' backcountry. The color refers to the average reflectance of a calm tropical lagoon at midday: a saturated, slightly muted blue-green with the optical clarity of shallow water over white sand. Brighter than reef, cooler than aquamarine, with the postcard weight of a Pacific atoll seen from above.

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.

#31c4e0
Original
#b0bde2
Protanopia
#99ace0
Deuteranopia
#00cfcd
Tritanopia
#a7a7a7
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
2.08:1
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
10.10:1

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
##31C4E0
Display P3
Display P3
color(display-p3 0.3860 0.7578 0.8646)
P3 has subtle headroomOKLCH chroma 0.123

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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