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Quickening Arbor Sky

#289de4
Notes

Quickening Arbor Sky (#289DE4) 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 (203°, 78%, 53%) 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 orange. For something softer, pull in its analogous neighbors on either side of the wheel.

HEX
#289de4
RGB
rgb(40, 157, 228)
HSL
hsl(203, 78%, 53%)
HWB
hwb(203 16% 11%)
OKLCH
oklch(66.7% 0.144 241.6)
P3
color(display-p3 0.3081 0.6069 0.8710)
HSV
hsv(203, 82%, 89%)
LAB
lab(61.79% -6.92 -44.66)
LCH
lch(61.79% 45.20 261.19)
CMYK
cmyk(82%, 31%, 0%, 11%)

Etymology

Quickening
adjective

Old English cwic, living / lively — present-participle of quicken. As a color modifier, quickening implies a saturated-and-coming-alive-and-active quality where the hue accelerates visual engagement. Sits at the bright-and-active end of the grid, parallel to animated and invigorating in usage.

Arbor
modifier

Latin arbor, tree-or-trunk. As a color modifier, arbor implies a Latin-tree-and-vine-arbor quality, the visual register of Pliny-Natural-History-and-Roman-villa-arbor hand-Latin-tree-and-vine-arbor Pliny-Natural-History-and-Roman-villa-arbor-and-pergola arbor-and-Latin-tree-and-vine-arbor surfaces under Pliny-Natural-History-and-Roman-villa-arbor-and-pergola Pompeii-and-Tuscan-pergola-and-grape-arbor leafy-shade-light. Sits at the modifier-and-Latin end of the grid, parallel to via and domus in usage.

Sky
noun

The blue of a clear sky at noon — produced by Rayleigh scattering, the preferential dispersion of shorter wavelengths through atmospheric molecules. Air itself is colorless; the color we see is sunlight scattered toward our eyes by every cubic kilometer above. The reference shade is mid-latitude noon under a high pressure system: a clean, slightly green-shifted blue with the luminous depth of light scattered across an entire hemisphere of air.

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.

#289de4
Original
#7b9fe7
Protanopia
#628ee3
Deuteranopia
#00afb6
Tritanopia
#898989
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
2.99:1
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
7.03:1

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
##289DE4
Display P3
Display P3
color(display-p3 0.3081 0.6069 0.8710)
P3 has subtle headroomOKLCH chroma 0.144

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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