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Bold Robe Sapphire

#0a51b8
Notes

Bold Robe Sapphire (#0A51B8) is a true azure 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 (216°, 90%, 38%) 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
#0a51b8
RGB
rgb(10, 81, 184)
HSL
hsl(216, 90%, 38%)
HWB
hwb(216 4% 28%)
OKLCH
oklch(46.2% 0.176 259.6)
HSV
hsv(216, 95%, 72%)
LAB
lab(36.76% 21.43 -59.69)
LCH
lch(36.76% 63.42 289.75)
CMYK
cmyk(95%, 56%, 0%, 28%)

Etymology

Bold
adjective

Old English beald, brave, courageous — a quality word that crossed over to color in the late seventeenth century. Bold describes a color that asserts itself: high saturation combined with mid lightness, where the hue presents itself without compromise. Sits at the center of the bold-bucket grid, near strong and rich. Closer to a presence word than a pigment word.

Robe
modifier

Old French robe, long-flowing-garment. As a color modifier, robe implies a long-flowing-and-academic-and-judicial quality, the visual register of Oxford-Cambridge-academic-and-judicial-robe hand-long-flowing-and-academic-and-judicial Oxford-Cambridge-academic-and-judicial-robe-and-monastic-habit robe-and-long-flowing-and-academic surfaces under Oxford-Cambridge-academic-and-judicial-robe-and-monastic-habit Senate-and-Inns-of-Court-and-cathedral-cloister Trinity-Senior-Common-Room-light. Sits at the modifier-and-textile end of the grid, parallel to gown and cope in usage.

Sapphire
noun

An iron-and-titanium-bearing corundum — the same mineral as ruby, hardness 9 on the Mohs scale, mined for two millennia from Sri Lanka, Burma, Madagascar, and the Cashmere mines of British India. The color refers to a fine Kashmir-cut sapphire: a saturated, slightly violet-shifted deep blue with the gem's signature internal velvet — a quality of light scattering in the stone that faceted glass cannot replicate. Cooler than cobalt, deeper than azure.

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.

#0a51b8
Original
#005ebc
Protanopia
#004fb6
Deuteranopia
#006b7c
Tritanopia
#494949
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).
AAAon White
7.29:1
The quick brown foxSample body text at normal size. The wcag minimum for body contrast is 4.5:1 (AA) or 7:1 (AAA).
Failon Black
2.88:1

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