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Rich Shu

#b52b07
Notes

Rich Shu (#B52B07) 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 (12°, 93%, 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
#b52b07
RGB
rgb(181, 43, 7)
HSL
hsl(12, 93%, 37%)
HWB
hwb(12 3% 29%)
OKLCH
oklch(50.8% 0.179 33.8)
HSV
hsv(12, 96%, 71%)
LAB
lab(40.52% 53.56 50.79)
LCH
lch(40.52% 73.81 43.48)
CMYK
cmyk(0%, 76%, 96%, 29%)

Etymology

Rich
adjective

Old French riche, wealthy, abundant — applied to color since the medieval period for hues that read as plentiful in pigment. Rich red, rich brown: the implication is depth combined with saturation, a color that gives the eye more to absorb. Sits at the saturated mid-light corner of the engine's grid, slightly warmer than bold and deeper than vivid.

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

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.

#b52b07
Original
#574c00
Protanopia
#796b00
Deuteranopia
#c80026
Tritanopia
#464646
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
6.34:1
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
3.31:1

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Canvas