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Functional Copenhagen

#42dde8
Notes

Functional Copenhagen (#42DDE8) 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°, 78%, 58%) places it in the highly saturated band at a mid lightness. Best used in small doses, like logos, CTAs, focus rings, or highlight text, where its saturation becomes a feature rather than noise. 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
#42dde8
RGB
rgb(66, 221, 232)
HSL
hsl(184, 78%, 58%)
HWB
hwb(184 26% 9%)
OKLCH
oklch(82.4% 0.126 202.1)
HSV
hsv(184, 72%, 91%)
LAB
lab(81.12% -35.80 -17.00)
LCH
lch(81.12% 39.63 205.40)
CMYK
cmyk(72%, 5%, 0%, 9%)

Etymology

Functional
adjective

Latin fūnctiō, performance — adjectival suffix -al. As a color modifier, functional implies a clear-and-purpose-fit-and-utilitarian quality, the crisp color of Mid-Century-Modern and Bauhaus form-follows-function design-aesthetic. Sits at the crisp-and-functional end of the grid, parallel to practical and utilitarian 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

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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.

#42dde8
Original
#ccd3e9
Protanopia
#b4c2e9
Deuteranopia
#00e6e0
Tritanopia
#bdbdbd
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
1.65:1
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
12.74:1

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Canvas