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Buttressed Rust

#ac441c
Notes

Buttressed Rust (#AC441C) is a true orange with a warm character. It leans warm, pulling light toward red, orange, and yellow. Naturally inviting, it suits editorial and hospitality contexts. Its HSL profile (17°, 72%, 39%) places it in the balanced band at a mid lightness. It works across type, buttons, and borders, saturated enough to feel deliberate but balanced enough to not fight the rest of the palette. 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
#ac441c
RGB
rgb(172, 68, 28)
HSL
hsl(17, 72%, 39%)
HWB
hwb(17 11% 33%)
OKLCH
oklch(52.2% 0.146 39.6)
HSV
hsv(17, 84%, 67%)
LAB
lab(42.75% 40.61 43.77)
LCH
lch(42.75% 59.71 47.15)
CMYK
cmyk(0%, 60%, 84%, 33%)

Etymology

Buttressed
adjective

Old French bouterez, thrusting-mass — past-participle of buttress, derived from bouter (to thrust). As a color modifier, buttressed implies a saturated-and-architecturally-supported quality, the deep-rich color of Gothic-Cathedral flying-buttress-and-rib-vault stone-architecture. Sits at the bold-and-fortified end of the grid, parallel to fortified and reinforced.

Rust
noun

Iron oxide — Fe₂O₃ — the slow union of iron with oxygen, accelerated by water and salt. The color is not the bright orange of fresh rust but the deeper, drier brown-red that forms after weeks of weather: the surface of an abandoned car, a Cor-Ten steel sculpture, the desert-varnished sandstone of the American Southwest. Earthier than copper, warmer than maroon.

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.

#ac441c
Original
#625616
Protanopia
#7b6e18
Deuteranopia
#bd2a3c
Tritanopia
#575757
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
5.84:1
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
3.60:1

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