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Resounding Earth

#155ad0
Notes

Resounding Earth (#155AD0) 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 (218°, 82%, 45%) 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 amber. For something softer, pull in its analogous neighbors on either side of the wheel.

HEX
#155ad0
RGB
rgb(21, 90, 208)
HSL
hsl(218, 82%, 45%)
HWB
hwb(218 8% 18%)
OKLCH
oklch(50.2% 0.194 260.9)
HSV
hsv(218, 90%, 82%)
LAB
lab(41.25% 25.48 -66.32)
LCH
lch(41.25% 71.04 291.02)
CMYK
cmyk(90%, 57%, 0%, 18%)

Etymology

Resounding
adjective

Latin resonāre, to echo back — present-participle of resound. As a color modifier, resounding implies a saturated-and-echoing-and-imposing quality where the hue reverberates visually like a cathedral-bell ring. Sits at the bold-and-resonant end of the grid, parallel to resonant and booming in usage.

Earth
noun

The third planet from the Sun — and the saturated deep blue of Earth seen from space, the pale blue dot of Carl Sagan's Voyager-1 image. Earth color refers to the average reflectance of Earth seen from low orbit: a saturated, slightly cool deep blue with the optical complexity of ocean-and-cloud-and-atmosphere reflectance.

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.

#155ad0
Original
#006ad4
Protanopia
#0059ce
Deuteranopia
#00788c
Tritanopia
#545454
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).
AAon White
6.17:1
The quick brown foxSample body text at normal size. The wcag minimum for body contrast is 4.5:1 (AA) or 7:1 (AAA).
AA Largeon Black
3.41:1

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