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Reposeful Neptune Kingfisher

#37a8b6
Notes

Reposeful Neptune Kingfisher (#37A8B6) is a true cyan with an earthy character. It leans grounded and natural, the kind of color that plays well with wood, clay, linen, and warm neutrals. Its HSL profile (187°, 54%, 46%) 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
#37a8b6
RGB
rgb(55, 168, 182)
HSL
hsl(187, 54%, 46%)
HWB
hwb(187 22% 29%)
OKLCH
oklch(67.5% 0.100 207.0)
P3
color(display-p3 0.3508 0.6498 0.7049)
HSV
hsv(187, 70%, 71%)
LAB
lab(63.50% -26.57 -16.40)
LCH
lch(63.50% 31.22 211.68)
CMYK
cmyk(70%, 8%, 0%, 29%)

Etymology

Reposeful
adjective

Latin repōnere, to put back — adjectival suffix -ful. As a color modifier, reposeful implies a clear-and-restful-and-still quality, the calm color of pre-modern monastic cloister-and-refectory meditative-and-silent interior architecture. Sits at the crisp-and-calm end of the grid, parallel to peaceful and placid in usage.

Neptune
modifier

Latin Neptunus, Roman-god-of-sea-and-eighth-planet. As a color modifier, neptune implies a Roman-god-of-sea-and-deep-blue-eighth-planet quality, the visual register of Roman-Neptune-and-Voyager-2-deep-blue hand-Roman-god-of-sea-and-deep-blue-eighth-planet Roman-Neptune-and-Voyager-2-deep-blue-and-Trevi-Fountain neptune-and-Roman-god-of-sea surfaces under Roman-Neptune-and-Voyager-2-deep-blue-and-Trevi-Fountain Voyager-2-flyby-and-Trevi-Fountain deep-blue-planet-light. Sits at the modifier-and-zodiac end of the grid, parallel to uranus and saturn in usage.

Kingfisher
noun

The family Alcedinidae — particularly Alcedo atthis, the European common kingfisher whose iridescent turquoise-blue plumage gives the color its name. The color refers to a male European kingfisher's wing: a saturated, slightly cool deep blue-green with the iridescent satin finish of structurally colored feathers.

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.

#37a8b6
Original
#9aa1b7
Protanopia
#8894b6
Deuteranopia
#00afac
Tritanopia
#919191
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
2.82:1
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
7.44:1

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
##37A8B6
Display P3
Display P3
color(display-p3 0.3508 0.6498 0.7049)
P3 has subtle headroomOKLCH chroma 0.100

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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