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Untroubled Lazuli

#51a5cc
Notes

Untroubled Lazuli (#51A5CC) is a true cyan with a cool character. It leans cool, sitting on the blue, green, and violet side of the wheel. Quiet and dependable, a fit for product UI and data visualization. Its HSL profile (199°, 55%, 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 orange. For something softer, pull in its analogous neighbors on either side of the wheel.

HEX
#51a5cc
RGB
rgb(81, 165, 204)
HSL
hsl(199, 55%, 56%)
HWB
hwb(199 32% 20%)
OKLCH
oklch(68.5% 0.099 230.7)
P3
color(display-p3 0.4023 0.6394 0.7848)
HSV
hsv(199, 60%, 80%)
LAB
lab(64.17% -13.91 -27.56)
LCH
lch(64.17% 30.87 243.23)
CMYK
cmyk(60%, 19%, 0%, 20%)

Etymology

Untroubled
adjective

Latin turbāre, to disturb — negative-prefix un- plus past-participle of trouble. As a color modifier, untroubled implies a clear-and-calm-and-undisturbed quality where the hue carries no visual agitation. Sits at the crisp-and-calm end of the grid, parallel to serene and placid in usage.

Lazuli
noun

Passerina amoena, the lazuli bunting — a North American songbird whose males display saturated deep-blue plumage with white wing bars and chestnut breasts. Named for the gemstone (lapis lazuli) the bird's plumage resembles. The color refers to a male lazuli bunting in breeding plumage: a saturated, slightly cool deep blue.

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.

#51a5cc
Original
#91a3ce
Protanopia
#8096cb
Deuteranopia
#00b0b2
Tritanopia
#969696
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
2.76:1
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
7.60:1

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
##51A5CC
Display P3
Display P3
color(display-p3 0.4023 0.6394 0.7848)
P3 has subtle headroomOKLCH chroma 0.099

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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