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Imperial Ruby

#a40527
Notes

Imperial Ruby (#A40527) is a deep 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 (347°, 94%, 33%) 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 teal. For something softer, pull in its analogous neighbors on either side of the wheel.

HEX
#a40527
RGB
rgb(164, 5, 39)
HSL
hsl(347, 94%, 33%)
HWB
hwb(347 2% 36%)
OKLCH
oklch(45.6% 0.181 20.8)
HSV
hsv(347, 97%, 64%)
LAB
lab(34.29% 57.75 28.65)
LCH
lch(34.29% 64.46 26.39)
CMYK
cmyk(0%, 97%, 76%, 36%)

Etymology

Imperial
adjective

From the Latin imperialis, of the empire — applied to color since the medieval period for the hues reserved for sovereigns and empires: imperial purple of Tyrian dye, imperial yellow of Ming-dynasty porcelain. As a modifier, imperial implies saturation combined with the institutional weight of a color owned by a court. Sits in the bold-and-deep corner, alongside royal.

Ruby
noun

From the Latin ruber — simply, red. The gemstone is a chromium-tinged corundum, harder than anything in nature except diamond, and so saturated that a fine Burmese pigeon's blood ruby at auction outpaces a comparable diamond by weight. The color borrows the gem's confidence: a clear, glassy red without the brown of garnet or the blue of crimson.

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.

#a40527
Original
#423c26
Protanopia
#665c21
Deuteranopia
#b50018
Tritanopia
#292929
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
7.99:1
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
2.63:1

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