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Coolazure

Rich Sapphire Ribbon

#6599cb
Notes

Rich Sapphire Ribbon (#6599CB) is a true 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 (209°, 50%, 60%) 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
#6599cb
RGB
rgb(101, 153, 203)
HSL
hsl(209, 50%, 60%)
HWB
hwb(209 40% 20%)
OKLCH
oklch(66.7% 0.093 248.4)
HSV
hsv(209, 50%, 80%)
LAB
lab(61.53% -3.36 -31.02)
LCH
lch(61.53% 31.20 263.83)
CMYK
cmyk(50%, 25%, 0%, 20%)

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.

#6599cb
Original
#859acd
Protanopia
#7790ca
Deuteranopia
#32a5aa
Tritanopia
#929292
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
3.01:1
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
6.97:1

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