colors
Back to gallery

Plutonian Cadet

#15318b
Notes

Plutonian Cadet (#15318B) 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 (226°, 74%, 31%) 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
#15318b
RGB
rgb(21, 49, 139)
HSL
hsl(226, 74%, 31%)
HWB
hwb(226 8% 45%)
OKLCH
oklch(35.8% 0.153 265.5)
P3
color(display-p3 0.1099 0.1896 0.5245)
HSV
hsv(226, 85%, 55%)
LAB
lab(24.38% 25.75 -52.70)
LCH
lch(24.38% 58.66 296.04)
CMYK
cmyk(85%, 65%, 0%, 45%)

Etymology

Plutonian
adjective

From Pluto, the Roman god of the underworld (Greek Plouton). As a color modifier, plutonian implies the cool deep darkness of the underworld realms, with literary-classical register. Sits at the deep-and-cool end of the grid, parallel to Hadean and cooler than infernal.

Cadet
noun

A pale gray-blue named for the dress uniform of military cadets — particularly the West Point cadet uniform and the British Royal Military College's traditional grays. The color refers to a cadet-uniform fabric: a soft, slightly muted gray-blue with the matte finish of regulation serge wool. Cooler than slate, warmer than steel, with the institutional weight of pre-officer formal dress.

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.

#15318b
Original
#00408e
Protanopia
#003589
Deuteranopia
#004959
Tritanopia
#323232
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
11.39:1
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
1.84:1

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
##15318B
Display P3
Display P3
color(display-p3 0.1099 0.1896 0.5245)
P3 has subtle headroomOKLCH chroma 0.153

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.

Related Colors

Canvas