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Bold Steller

#173ea9
Notes

Bold Steller (#173EA9) 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 (224°, 76%, 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
#173ea9
RGB
rgb(23, 62, 169)
HSL
hsl(224, 76%, 38%)
HWB
hwb(224 9% 34%)
OKLCH
oklch(41.3% 0.177 264.4)
P3
color(display-p3 0.1314 0.2397 0.6381)
HSV
hsv(224, 86%, 66%)
LAB
lab(30.62% 28.92 -60.80)
LCH
lch(30.62% 67.33 295.44)
CMYK
cmyk(86%, 63%, 0%, 34%)

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.

Steller
noun

Cyanocitta stelleri, the Steller's jay — named for German naturalist Georg Wilhelm Steller, who collected the type specimen on the 1741 Bering Expedition. The males display saturated deep-blue plumage with black crests. The color refers to a male Steller's jay in fresh plumage: a saturated, slightly cool deep blue with the matte finish of structurally-colored corvid feathers.

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.

#173ea9
Original
#004fac
Protanopia
#0041a7
Deuteranopia
#005a6d
Tritanopia
#3d3d3d
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
9.14:1
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
2.30:1

Wide gamut

Display P3 representation

The CSS Color 4 wide-gamut form of this color. Both swatches render the same color on every display — the P3 form only diverges from sRGB when a designer pushes channels outside sRGB's reach.

sRGB hex
sRGB hex
##173EA9
Display P3
Display P3
color(display-p3 0.1314 0.2397 0.6381)
P3 has subtle headroomOKLCH chroma 0.177

Moderately saturated colors gain a small bump in P3 — the difference is usually visible side-by-side on wide-gamut hardware but won't change the character of the color.

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