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Charged Nautilus

#21d9c0
Notes

Charged Nautilus (#21D9C0) is a true teal with a vibrant character. It holds its own as a focal accent, carrying visual weight without tipping into neon territory. Its HSL profile (172°, 74%, 49%) 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
#21d9c0
RGB
rgb(33, 217, 192)
HSL
hsl(172, 74%, 49%)
HWB
hwb(172 13% 15%)
OKLCH
oklch(79.6% 0.140 180.2)
P3
color(display-p3 0.4040 0.8386 0.7551)
HSV
hsv(172, 85%, 85%)
LAB
lab(78.32% -48.32 0.12)
LCH
lch(78.32% 48.32 179.85)
CMYK
cmyk(85%, 0%, 12%, 15%)

Etymology

Charged
adjective

Old French chargier, to load — past-participle of charge, sharing root with cargo. As a color modifier, charged implies a saturated-and-electrically-loaded quality where the hue carries visual potential-energy. Sits at the bright-and-active end of the grid, parallel to electrified and energetic in usage.

Nautilus
noun

Nautilus pompilius, the chambered nautilus — a living-fossil cephalopod whose mother-of-pearl interior shell is the source of abalone-style iridescence. Nautilus color refers to the inner shell of a polished nautilus: a soft, slightly cool pale blue-green with the iridescent satin finish of nacreous biomineral.

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.

#21d9c0
Original
#cfcbbf
Protanopia
#b9bbc2
Deuteranopia
#00ddd1
Tritanopia
#b0b0b0
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
1.79:1
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
11.75:1

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
##21D9C0
Display P3
Display P3
color(display-p3 0.4040 0.8386 0.7551)
P3 has subtle headroomOKLCH chroma 0.140

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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