colors
Back to gallery

Sterile Moot Lagoon

#31b5da
Notes

Sterile Moot Lagoon (#31B5DA) 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 (193°, 70%, 52%) 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
#31b5da
RGB
rgb(49, 181, 218)
HSL
hsl(193, 70%, 52%)
HWB
hwb(193 19% 15%)
OKLCH
oklch(72.0% 0.121 221.6)
P3
color(display-p3 0.3612 0.6998 0.8392)
HSV
hsv(193, 78%, 85%)
LAB
lab(68.58% -22.46 -28.58)
LCH
lch(68.58% 36.35 231.83)
CMYK
cmyk(78%, 17%, 0%, 15%)

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.

Moot
modifier

Old English mōt, meeting-or-debate-point. As a color modifier, moot implies a debated-and-suspended-and-undecided quality, the visual register of Anglo-Saxon-witenagemot-and-Inns-of-Court-moot hand-argued-and-suspended Anglo-Saxon-witenagemot-and-medieval-moot-court witenagemot-and-Inns-of-Court-and-shire-court mooted-and-debated surfaces under Anglo-Saxon-witenagemot-and-Inns-of-Court oak-bench-and-vellum debate-hall-light. Sits at the modifier-and-mood end of the grid, parallel to void and blank 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.

#31b5da
Original
#9fb0dc
Protanopia
#89a0da
Deuteranopia
#00c1c1
Tritanopia
#9c9c9c
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
2.40:1
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
8.75:1

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
##31B5DA
Display P3
Display P3
color(display-p3 0.3612 0.6998 0.8392)
P3 has subtle headroomOKLCH chroma 0.121

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.

Related Colors

Canvas