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Steady Sininen

#40dedd
Notes

Steady Sininen (#40DEDD) 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 (180°, 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
#40dedd
RGB
rgb(64, 222, 221)
HSL
hsl(180, 71%, 56%)
HWB
hwb(180 25% 13%)
OKLCH
oklch(82.2% 0.127 194.3)
P3
color(display-p3 0.4515 0.8586 0.8608)
HSV
hsv(180, 71%, 87%)
LAB
lab(81.04% -39.64 -11.27)
LCH
lch(81.04% 41.21 195.87)
CMYK
cmyk(71%, 0%, 0%, 13%)

Etymology

Steady
adjective

Old English stede, place, position — drifted to mean firm and unmoving. Used as a color modifier since the seventeenth century for hues that read as reliable rather than dramatic. Steady gray, steady green: moderate saturation combined with optical calmness. Sits in the crisp-bucket center alongside settled.

Sininen
noun

The Finnish word for blue — used for the Suomenlippu (Finnish flag) and the saturated blue of Finnish lake water. Sininen covers the entire blue-cyan spectrum in Finnish color vocabulary. The color refers to a Finnish lake at midsummer: a saturated, slightly cool deep blue with the optical depth of clear glacial-lake water.

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.

#40dedd
Original
#d0d3dd
Protanopia
#b9c2de
Deuteranopia
#00e5dd
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
1.65:1
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
12.71:1

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
##40DEDD
Display P3
Display P3
color(display-p3 0.4515 0.8586 0.8608)
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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