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Calm Loch

#66addf
Notes

Calm Loch (#66ADDF) is a true azure with a vibrant character. It holds its own as a focal accent, carrying visual weight without tipping into neon territory. Its HSL profile (205°, 65%, 64%) 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 orange. For something softer, pull in its analogous neighbors on either side of the wheel.

HEX
#66addf
RGB
rgb(102, 173, 223)
HSL
hsl(205, 65%, 64%)
HWB
hwb(205 40% 13%)
OKLCH
oklch(72.1% 0.102 240.9)
P3
color(display-p3 0.4655 0.6715 0.8567)
HSV
hsv(205, 54%, 87%)
LAB
lab(68.05% -8.25 -32.00)
LCH
lch(68.05% 33.05 255.54)
CMYK
cmyk(54%, 22%, 0%, 13%)

Etymology

Calm
adjective

Latin calma, heat of the day — paradoxically drifted in Italian to mean stillness. Used as a color modifier since the seventeenth century for hues that read as untroubled. Calm blue, calm gray: moderate saturation combined with optical quiet. Sits at the crisp-bucket near quiet and steady.

Loch
noun

The Scottish word for lake (from Gaelic loch) — particularly the saturated deep blue of Loch Ness, Loch Lomond, and the highland lochs of the western Highlands. Loch color refers to Loch Lomond at midday: a saturated, slightly cool deep blue with the optical depth of cold-water highland lake.

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.

#66addf
Original
#97ade1
Protanopia
#86a0de
Deuteranopia
#09b9be
Tritanopia
#a2a2a2
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
2.44:1
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
8.61:1

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
##66ADDF
Display P3
Display P3
color(display-p3 0.4655 0.6715 0.8567)
P3 has subtle headroomOKLCH chroma 0.102

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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