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Open Paraiba

#01808d
Notes

Open Paraiba (#01808D) is a deep cyan with a jewel character. It carries the deep, saturated richness of a gemstone. Authoritative and slightly formal, it works well for type and heavy UI elements. Its HSL profile (186°, 99%, 28%) places it in the highly saturated band at a dark 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 red. For something softer, pull in its analogous neighbors on either side of the wheel.

HEX
#01808d
RGB
rgb(1, 128, 141)
HSL
hsl(186, 99%, 28%)
HWB
hwb(186 0% 45%)
OKLCH
oklch(54.8% 0.094 207.3)
HSV
hsv(186, 99%, 55%)
LAB
lab(48.72% -24.44 -15.43)
LCH
lch(48.72% 28.90 212.26)
CMYK
cmyk(99%, 9%, 0%, 45%)

Etymology

Open
adjective

Old English open, unobstructed — used as a color modifier since the eighteenth century for hues that read as airy or uncrowded. Open blue, open green: moderate saturation combined with optical spaciousness, the slight visual breath of a hue that doesn't crowd the surface it covers. Sits at the crisp-bucket center alongside clear.

Paraiba
noun

The intensely-blue copper-bearing variety of tourmaline — discovered in 1989 in the Brazilian state of Paraíba. Paraiba tourmaline is one of the most expensive gem materials by weight. The color refers to a faceted Paraiba tourmaline: a saturated, slightly cool electric blue-green with the gem's signature internal fire.

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.

#01808d
Original
#737a8e
Protanopia
#636f8d
Deuteranopia
#008684
Tritanopia
#666666
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
4.69:1
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
4.47:1

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