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Certain Haori Cerulean

#297ccb
Notes

Certain Haori Cerulean (#297CCB) 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°, 66%, 48%) 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
#297ccb
RGB
rgb(41, 124, 203)
HSL
hsl(209, 66%, 48%)
HWB
hwb(209 16% 20%)
OKLCH
oklch(57.7% 0.144 251.1)
HSV
hsv(209, 80%, 80%)
LAB
lab(50.92% 3.40 -47.86)
LCH
lch(50.92% 47.98 274.06)
CMYK
cmyk(80%, 39%, 0%, 20%)

Etymology

Certain
adjective

Latin certus, fixed / sure — sharing root with English concern and certify. As a color modifier, certain implies a saturated-and-unambiguous quality where the hue declares its character without hesitation. Sits at the bold-and-confident end of the grid, parallel to assured and decisive in usage.

Haori
modifier

Japanese haori, short-jacket-over-kimono. As a color modifier, haori implies a Japanese-haori-and-short-jacket-over-kimono quality, the visual register of Edo-and-Meiji-haori-jacket hand-Japanese-haori-and-short-jacket-over-kimono Edo-and-Meiji-haori-jacket-and-Kyoto-Nishijin-and-Tokyo-Asakusa haori-and-Japanese-haori-and-short-jacket surfaces under Edo-and-Meiji-haori-jacket-and-Kyoto-Nishijin-and-Tokyo-Asakusa Edo-Tokugawa-and-Meiji-Tokyo Japanese-jacket-light. Sits at the modifier-and-textile end of the grid, parallel to kimono and sari in usage.

Cerulean
noun

From the Latin caeruleum, originally referring to dark blue paint pigment of the Roman world, then via French céruléen into English. As a modern art-supply name, cerulean blue is the cobalt-tin oxide pigment introduced in 1805. The color refers to a clean, slightly green-shifted blue with the matte finish of mineral pigment in linseed oil: lighter than cobalt, deeper than aqua, with the painter's weight of a word for sky.

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.

#297ccb
Original
#5681ce
Protanopia
#3c73c9
Deuteranopia
#008f9a
Tritanopia
#707070
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
4.34:1
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
4.84:1

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