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Idyllic Catacomb

#170534
Notes

Idyllic Catacomb (#170534) is a deep indigo 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 (263°, 82%, 11%) 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 lime. For something softer, pull in its analogous neighbors on either side of the wheel.

HEX
#170534
RGB
rgb(23, 5, 52)
HSL
hsl(263, 82%, 11%)
HWB
hwb(263 2% 80%)
OKLCH
oklch(18.6% 0.086 294.3)
P3
color(display-p3 0.0809 0.0226 0.1949)
HSV
hsv(263, 90%, 20%)
LAB
lab(4.87% 20.61 -26.37)
LCH
lch(4.87% 33.47 308.01)
CMYK
cmyk(56%, 90%, 0%, 80%)

Etymology

Idyllic
adjective

Greek eidúllion, little-poem — adjectival suffix -ic. As a color modifier, idyllic implies a neutral-and-pastoral-and-perfect-rural quality, the neutral color of Theocritus-and-Virgil-Eclogues idyllic-and-poetic-rural pastoral-mood color treatment. Sits at the neutral-and-traditional end of the grid, parallel to bucolic and pastoral in usage.

Catacomb
noun

Greek katà-kymbas, near-the-hollows — the deep-cool-gray underground burial-passageways of Roman-and-early-Christian periods, particularly the San Callisto and Domitilla catacomb-systems of Via Appia. Catacomb color refers to a San-Callisto 3rd-century catacomb-passage in candlelight: a dark cool-gray with the matte finish of Roman-tufa hand-quarried Via-Appia Roman-Christian fossors tunnel-construction.

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.

#170534
Original
#001135
Protanopia
#001033
Deuteranopia
#0e111c
Tritanopia
#0c0c0c
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
18.96:1
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
1.11:1

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
##170534
Display P3
Display P3
color(display-p3 0.0809 0.0226 0.1949)
P3 has subtle headroomOKLCH chroma 0.086

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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