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Reliable Boom Sky

#78cdf9
Notes

Reliable Boom Sky (#78CDF9) is a soft azure 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 (200°, 91%, 72%) places it in the highly saturated band at a light 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
#78cdf9
RGB
rgb(120, 205, 249)
HSL
hsl(200, 91%, 72%)
HWB
hwb(200 47% 2%)
OKLCH
oklch(81.1% 0.103 232.6)
P3
color(display-p3 0.5496 0.7956 0.9593)
HSV
hsv(200, 52%, 98%)
LAB
lab(78.75% -13.93 -29.52)
LCH
lch(78.75% 32.65 244.73)
CMYK
cmyk(52%, 18%, 0%, 2%)

Etymology

Reliable
adjective

Latin re-ligāre, to bind back — adjectival suffix -able. As a color modifier, reliable implies a clear-and-trustworthy-and-consistent quality where the hue carries the visual register of dependable-and-consistent design-element. Sits at the crisp-and-honest end of the grid, parallel to dependable and trustworthy in usage.

Boom
modifier

Dutch boom, tree / spar. As a color modifier, boom implies a horizontal-spar-attached-to-mast quality, the visual register of Tall-Ship-and-yacht-boom hand-cut horizontal-spar-attached-to-mast-foot boom-and-mainsail tall-ship-and-yacht maritime-rigging surfaces under tall-ship-and-yacht boom-and-mainsail maritime light. Sits at the modifier-and-nautical end of the grid, parallel to spar and mast 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.

#78cdf9
Original
#b8cbfb
Protanopia
#a5bdf8
Deuteranopia
#26d9db
Tritanopia
#bebebe
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
1.76:1
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
11.90:1

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
##78CDF9
Display P3
Display P3
color(display-p3 0.5496 0.7956 0.9593)
P3 has subtle headroomOKLCH chroma 0.103

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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