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Reliable Copenhagen

#40deda
Notes

Reliable Copenhagen (#40DEDA) 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 (178°, 71%, 56%) 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
#40deda
RGB
rgb(64, 222, 218)
HSL
hsl(178, 71%, 56%)
HWB
hwb(178 25% 13%)
OKLCH
oklch(82.1% 0.127 192.4)
P3
color(display-p3 0.4515 0.8586 0.8500)
HSV
hsv(178, 71%, 87%)
LAB
lab(80.95% -40.47 -9.80)
LCH
lch(80.95% 41.64 193.62)
CMYK
cmyk(71%, 0%, 2%, 13%)

Etymology

Reliable
adjective

Latin re-ligāre, to bind back — adjectival suffix -able. As a color modifier, reliable implies a clear-and-trustworthy-and-consistent quality where the hue carries the visual register of dependable-and-consistent design-element. Sits at the crisp-and-honest end of the grid, parallel to dependable and trustworthy in usage.

Copenhagen
noun

The Danish capital — and the saturated deep blue of Nyhavn canal water at midday and the Copenhagen Royal Porcelain underglaze produced since 1775. Copenhagen refers to a Royal Copenhagen Blue Fluted underglaze: a saturated, slightly cool deep blue with the high gloss of fired cobalt-on-porcelain.

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.

#40deda
Original
#d0d3da
Protanopia
#b9c2db
Deuteranopia
#00e4dc
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
1.66:1
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
12.68:1

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
##40DEDA
Display P3
Display P3
color(display-p3 0.4515 0.8586 0.8500)
P3 has subtle headroomOKLCH chroma 0.127

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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