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Princely Shu

#b91304
Notes

Princely Shu (#B91304) is a true red 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 (5°, 96%, 37%) 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 cyan. For something softer, pull in its analogous neighbors on either side of the wheel.

HEX
#b91304
RGB
rgb(185, 19, 4)
HSL
hsl(5, 96%, 37%)
HWB
hwb(5 2% 27%)
OKLCH
oklch(50.0% 0.197 30.1)
HSV
hsv(5, 98%, 73%)
LAB
lab(39.23% 60.65 51.58)
LCH
lch(39.23% 79.62 40.38)
CMYK
cmyk(0%, 90%, 98%, 27%)

Etymology

Princely
adjective

Latin prīnceps, first / chief — adjectival suffix -ly. As a color modifier, princely implies a saturated-and-royal-secondary quality, the deep-rich color of European crown-prince coronet-and-livery vestment. Sits at the bold-and-aristocratic end of the grid, parallel to lordly and regal in usage.

Shu
noun

Vermillion in Japanese — specifically the cinnabar-derived pigment used since the Heian period to paint Shinto torii gates, temple beams, and the lacquer of imperial seals. The color refers to a freshly painted Inari Shrine torii: a saturated, slightly orange red with the high gloss of layered urushi lacquer. Brighter than crimson, deeper than tangerine, with the sacred-architectural weight of a color reserved for thresholds between human and divine.

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

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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.

#b91304
Original
#504600
Protanopia
#776900
Deuteranopia
#cd0014
Tritanopia
#353535
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).
AAon White
6.65:1
The quick brown foxSample body text at normal size. The wcag minimum for body contrast is 4.5:1 (AA) or 7:1 (AAA).
AA Largeon Black
3.16:1

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