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Certain Russet

#aa1d0a
Notes

Certain Russet (#AA1D0A) 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 (7°, 89%, 35%) 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
#aa1d0a
RGB
rgb(170, 29, 10)
HSL
hsl(7, 89%, 35%)
HWB
hwb(7 4% 33%)
OKLCH
oklch(47.6% 0.178 31.0)
HSV
hsv(7, 94%, 67%)
LAB
lab(36.84% 54.38 46.44)
LCH
lch(36.84% 71.51 40.50)
CMYK
cmyk(0%, 83%, 94%, 33%)

Etymology

Certain
adjective

Latin certus, fixed / sure — sharing root with English concern and certify. As a color modifier, certain implies a saturated-and-unambiguous quality where the hue declares its character without hesitation. Sits at the bold-and-confident end of the grid, parallel to assured and decisive in usage.

Russet
noun

From the Old French rousset, reddish-brown. A medieval term for the coarse, undyed wool of peasant cloth — the natural red-brown of the local fleece. The color now refers to autumn foliage, the skin of a russet potato, the rust-stained sandstone of the American southwest. Earthier than rust, drier than mahogany; the red of October.

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.

#aa1d0a
Original
#4d4303
Protanopia
#6f6200
Deuteranopia
#bc001c
Tritanopia
#3a3a3a
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
7.27:1
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
2.89:1

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Canvas