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Healthful Lone Turquoise

#21b8c2
Notes

Healthful Lone Turquoise (#21B8C2) 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 (184°, 71%, 45%) 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
#21b8c2
RGB
rgb(33, 184, 194)
HSL
hsl(184, 71%, 45%)
HWB
hwb(184 13% 24%)
OKLCH
oklch(71.5% 0.116 202.1)
P3
color(display-p3 0.3451 0.7111 0.7523)
HSV
hsv(184, 83%, 76%)
LAB
lab(68.38% -33.02 -15.71)
LCH
lch(68.38% 36.57 205.44)
CMYK
cmyk(83%, 5%, 0%, 24%)

Etymology

Healthful
adjective

Old English hǣlth, health — adjectival suffix -ful. As a color modifier, healthful implies a clear-and-vital-and-wholesome quality where the hue carries the visual register of fresh-air-and-sunlight outdoor health-promoting environment. Sits at the crisp-and-wholesome end of the grid, parallel to salubrious and wholesome in usage.

Lone
modifier

Middle English lone, shortened from alone. As a color modifier, lone implies a solitary-and-singular-and-isolated quality, the visual register of Caspar-David-Friedrich-Wanderer-and-lone-pine hand-solitary-and-singular-and-isolated Caspar-David-Friedrich-Wanderer-and-lone-pine-and-Romantic-vista loned-and-solitary-and-singular-and-isolated surfaces under Caspar-David-Friedrich-Wanderer-and-lone-pine-and-Romantic-vista mountaintop-and-empty-shore single-figure-light. Sits at the modifier-and-mood end of the grid, parallel to void and drear in usage.

Turquoise
noun

The hydrated copper-aluminum phosphate mined in Persia and the American Southwest for thousands of years — the firuze of Iran, the chalchihuitl of Mesoamerica, the heart of Pueblo and Navajo silverwork. The color refers to a fine Sleeping Beauty turquoise from Arizona: a saturated, slightly green-shifted blue with the slight matrix of host-rock veining. Brighter than persian, lighter than cerulean.

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.

#21b8c2
Original
#a9b0c3
Protanopia
#94a0c3
Deuteranopia
#00c0bb
Tritanopia
#999999
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
2.41:1
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
8.70:1

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
##21B8C2
Display P3
Display P3
color(display-p3 0.3451 0.7111 0.7523)
P3 has subtle headroomOKLCH chroma 0.116

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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