colors
Back to gallery

Clean Lull Lagoon

#21b3d3
Notes

Clean Lull Lagoon (#21B3D3) 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 (191°, 73%, 48%) 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
#21b3d3
RGB
rgb(33, 179, 211)
HSL
hsl(191, 73%, 48%)
HWB
hwb(191 13% 17%)
OKLCH
oklch(70.9% 0.121 217.6)
P3
color(display-p3 0.3363 0.6917 0.8130)
HSV
hsv(191, 84%, 83%)
LAB
lab(67.47% -25.14 -26.45)
LCH
lch(67.47% 36.49 226.45)
CMYK
cmyk(84%, 15%, 0%, 17%)

Etymology

Clean
adjective

Old English clǣne, pure, free of dirt — used as a color modifier since the medieval period for hues that read as crisp and uncontaminated by other pigments. Clean white, clean blue: moderate saturation combined with optical clarity. Sits at the crisp-bucket center alongside clear and true.

Lull
modifier

Middle English lullen, to-sing-to-sleep. As a color modifier, lull implies a hushed-and-pacified-and-cradled quality, the visual register of cradle-song-and-vesper-lull hand-cradled-and-rocked cradle-and-cot-and-crib hand-rocked-and-sung-to-lulled-and-cradled lulled-and-cradled surfaces under cradle-song-and-vesper hush-and-quiet-and-still bedside-and-nursery-light. Sits at the modifier-and-mood end of the grid, parallel to hush and soothe 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.

#21b3d3
Original
#9eaed5
Protanopia
#889dd3
Deuteranopia
#00bebd
Tritanopia
#969696
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
2.48:1
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
8.45:1

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
##21B3D3
Display P3
Display P3
color(display-p3 0.3363 0.6917 0.8130)
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