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Buttressed Carthage

#641c8b
Notes

Buttressed Carthage (#641C8B) is a deep indigo 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 (279°, 66%, 33%) places it in the balanced band at a dark lightness. It works well as a headline, icon, or deep background in an otherwise light layout, pairing cleanly with cream, bone, and warm neutrals. For a confident two-color system, pair it with its complementary lime. For something softer, pull in its analogous neighbors on either side of the wheel.

HEX
#641c8b
RGB
rgb(100, 28, 139)
HSL
hsl(279, 66%, 33%)
HWB
hwb(279 11% 45%)
OKLCH
oklch(40.0% 0.173 310.1)
P3
color(display-p3 0.3605 0.1307 0.5252)
HSV
hsv(279, 80%, 55%)
LAB
lab(27.86% 49.58 -46.72)
LCH
lch(27.86% 68.12 316.70)
CMYK
cmyk(28%, 80%, 0%, 45%)

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.

Carthage
noun

Phoenician colonial capital on the Tunis coast (founded 814 BCE) — and a major secondary Tyrian purple production site supplying the western Mediterranean trade network. Carthage color refers to a Carthaginian trade-textile fragment from the Byrsa hill citadel: a saturated, slightly cool deep violet with the matte finish of multi-bath Bolinus brandaris shellfish dye on hand-loomed Punic wool.

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.

#641c8b
Original
#003f8e
Protanopia
#004389
Deuteranopia
#5e3853
Tritanopia
#333333
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
10.09:1
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
2.08:1

Wide gamut

Display P3 representation

The CSS Color 4 wide-gamut form of this color. Both swatches render the same color on every display — the P3 form only diverges from sRGB when a designer pushes channels outside sRGB's reach.

sRGB hex
sRGB hex
##641C8B
Display P3
Display P3
color(display-p3 0.3605 0.1307 0.5252)
P3 has subtle headroomOKLCH chroma 0.173

Moderately saturated colors gain a small bump in P3 — the difference is usually visible side-by-side on wide-gamut hardware but won't change the character of the color.

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