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Useful Mast Turquoise

#51dad0
Notes

Useful Mast Turquoise (#51DAD0) 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 (176°, 65%, 59%) 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
#51dad0
RGB
rgb(81, 218, 208)
HSL
hsl(176, 65%, 59%)
HWB
hwb(176 32% 15%)
OKLCH
oklch(81.2% 0.118 188.3)
P3
color(display-p3 0.4756 0.8437 0.8132)
HSV
hsv(176, 63%, 85%)
LAB
lab(79.86% -39.00 -6.05)
LCH
lch(79.86% 39.47 188.82)
CMYK
cmyk(63%, 0%, 5%, 15%)

Etymology

Useful
adjective

Latin ūsus, use — adjectival suffix -ful. As a color modifier, useful implies a clear-and-purpose-serving quality where the hue carries the visual register of helpful-and-supporting design-element. Sits at the crisp-and-functional end of the grid, parallel to practical and serviceable in usage.

Mast
modifier

Old English mæst, long-pole. As a color modifier, mast implies a tall-pole-with-sails quality, the visual register of Tall-Ship-and-Royal-Navy-Mast hand-rigged tall-mast-with-sail-and-yard tall-ship-and-frigate maritime-architecture surfaces under tall-ship-mast-and-yard maritime-overhead light. Sits at the modifier-and-nautical end of the grid, parallel to spar and boom 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.

#51dad0
Original
#cfcfd0
Protanopia
#bac0d1
Deuteranopia
#00dfd7
Tritanopia
#bcbcbc
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
1.71:1
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
12.29:1

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
##51DAD0
Display P3
Display P3
color(display-p3 0.4756 0.8437 0.8132)
P3 has subtle headroomOKLCH chroma 0.118

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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