colors
Back to gallery

Sure Copenhagen

#256b6a
Notes

Sure Copenhagen (#256B6A) is a deep 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 (179°, 49%, 28%) places it in the balanced band at a dark lightness. It works well as a headline, icon, or deep background in an otherwise light layout, pairing cleanly with cream, bone, and warm neutrals. 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
#256b6a
RGB
rgb(37, 107, 106)
HSL
hsl(179, 49%, 28%)
HWB
hwb(179 15% 58%)
OKLCH
oklch(48.4% 0.069 193.8)
P3
color(display-p3 0.2247 0.4138 0.4130)
HSV
hsv(179, 65%, 42%)
LAB
lab(41.13% -21.62 -5.89)
LCH
lch(41.13% 22.40 195.24)
CMYK
cmyk(65%, 0%, 1%, 58%)

Etymology

Sure
adjective

Old French seur, certain — used as a color modifier since the medieval period for hues that read as confident and stable. Sure red, sure blue: moderate saturation combined with optical commitment. Sits at the crisp-bucket center alongside steady and true.

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.

#256b6a
Original
#64666a
Protanopia
#595e6b
Deuteranopia
#006e6a
Tritanopia
#5c5c5c
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).
AAon White
6.19:1
The quick brown foxSample body text at normal size. The wcag minimum for body contrast is 4.5:1 (AA) or 7:1 (AAA).
AA Largeon Black
3.39:1

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
##256B6A
Display P3
Display P3
color(display-p3 0.2247 0.4138 0.4130)
Inside sRGBOKLCH chroma 0.069

This color sits well within the sRGB cube. P3 and sRGB share the gray axis and most desaturated tones, so a P3 display renders this identically to an sRGB display.

Related Colors

Canvas