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Shaded Observatory

#173177
Notes

Shaded Observatory (#173177) is a deep 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°, 68%, 28%) places it in the balanced band at a dark lightness. It works well as a headline, icon, or deep background in an otherwise light layout, pairing cleanly with cream, bone, and warm neutrals. 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
#173177
RGB
rgb(23, 49, 119)
HSL
hsl(224, 68%, 28%)
HWB
hwb(224 9% 53%)
OKLCH
oklch(34.0% 0.124 265.0)
P3
color(display-p3 0.1149 0.1897 0.4496)
HSV
hsv(224, 81%, 47%)
LAB
lab(22.69% 17.80 -42.88)
LCH
lch(22.69% 46.43 292.54)
CMYK
cmyk(81%, 59%, 0%, 53%)

Etymology

Shaded
adjective

Old English sceadwian, to cover with shadow — past-participle of shade. As a color modifier, shaded implies a hue darkened by overhead-foliage-or-architectural-element occlusion in pre-modern garden-and-courtyard tradition. Sits at the deep-and-obscured end of the grid, parallel to shadowy but more architectural in connotation.

Observatory
noun

An astronomical research facility — particularly the deep-blue interior paint of optical observatories like Mount Wilson, Palomar, and Mauna Kea. The deep blue minimizes stray-light reflection inside the dome. The color refers to the painted interior of a research-grade optical observatory: a saturated, slightly cool very deep blue with the matte finish of low-reflectance enamel.

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.

#173177
Original
#003b79
Protanopia
#003276
Deuteranopia
#00424f
Tritanopia
#313131
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
12.05:1
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
1.74:1

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
##173177
Display P3
Display P3
color(display-p3 0.1149 0.1897 0.4496)
P3 has subtle headroomOKLCH chroma 0.124

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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