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Smoldering Cerulean

#378ad8
Notes

Smoldering Cerulean (#378AD8) 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 (209°, 67%, 53%) 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
#378ad8
RGB
rgb(55, 138, 216)
HSL
hsl(209, 67%, 53%)
HWB
hwb(209 22% 15%)
OKLCH
oklch(62.0% 0.142 250.1)
HSV
hsv(209, 75%, 85%)
LAB
lab(56.03% 1.34 -47.06)
LCH
lch(56.03% 47.08 271.63)
CMYK
cmyk(75%, 36%, 0%, 15%)

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

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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.

#378ad8
Original
#668edb
Protanopia
#4e80d6
Deuteranopia
#009da7
Tritanopia
#7e7e7e
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).
AA Largeon White
3.63:1
The quick brown foxSample body text at normal size. The wcag minimum for body contrast is 4.5:1 (AA) or 7:1 (AAA).
AAon Black
5.79:1

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