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Occluded Observatory

#153699
Notes

Occluded Observatory (#153699) is a deep blue 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 (225°, 76%, 34%) 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 amber. For something softer, pull in its analogous neighbors on either side of the wheel.

HEX
#153699
RGB
rgb(21, 54, 153)
HSL
hsl(225, 76%, 34%)
HWB
hwb(225 8% 40%)
OKLCH
oklch(38.1% 0.166 264.9)
P3
color(display-p3 0.1162 0.2088 0.5774)
HSV
hsv(225, 86%, 60%)
LAB
lab(27.01% 27.89 -57.03)
LCH
lch(27.01% 63.48 296.06)
CMYK
cmyk(86%, 65%, 0%, 40%)

Etymology

Occluded
adjective

Latin occludere, to close up — past-participle of occlude. As a color modifier, occluded implies a hue blocked-and-dimmed by an intervening physical barrier. Sits at the deep-and-obscured end of the grid, parallel to eclipsed and cloaked but more clinical in register.

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.

#153699
Original
#00469c
Protanopia
#003a97
Deuteranopia
#005062
Tritanopia
#363636
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
10.40:1
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
2.02:1

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
##153699
Display P3
Display P3
color(display-p3 0.1162 0.2088 0.5774)
P3 has subtle headroomOKLCH chroma 0.166

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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