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Robust Plot Ruby

#a91524
Notes

Robust Plot Ruby (#A91524) 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 (354°, 78%, 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 teal. For something softer, pull in its analogous neighbors on either side of the wheel.

HEX
#a91524
RGB
rgb(169, 21, 36)
HSL
hsl(354, 78%, 37%)
HWB
hwb(354 8% 34%)
OKLCH
oklch(47.2% 0.179 23.7)
HSV
hsv(354, 88%, 66%)
LAB
lab(36.18% 56.53 32.87)
LCH
lch(36.18% 65.39 30.18)
CMYK
cmyk(0%, 88%, 79%, 34%)

Etymology

Robust
adjective

From the Latin robustus, of oak — implying strength combined with substance. As a color modifier, robust describes saturation combined with body: a robust burgundy, a robust olive. Sits in the bold-and-warm corner alongside strong and solid, with the slightly textural implication of a color that has substance behind the pigment.

Plot
modifier

Old English plot, small-piece-of-ground. As a color modifier, plot implies a tilled-garden-bed quality, the visual register of English-cottage-garden-and-allotment hand-tilled-and-cultivated small market-garden vegetable-bed surfaces under English-cottage-garden-and-allotment summer-tilling light. Sits at the modifier-and-place end of the grid, parallel to yard and garden in usage.

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

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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.

#a91524
Original
#484123
Protanopia
#6b601e
Deuteranopia
#bb001d
Tritanopia
#363636
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
7.45:1
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
2.82:1

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