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Buttressed Rex

#ad33b0
Notes

Buttressed Rex (#AD33B0) is a true violet with an earthy character. It leans grounded and natural, the kind of color that plays well with wood, clay, linen, and warm neutrals. Its HSL profile (299°, 55%, 45%) 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 green. For something softer, pull in its analogous neighbors on either side of the wheel.

HEX
#ad33b0
RGB
rgb(173, 51, 176)
HSL
hsl(299, 55%, 45%)
HWB
hwb(299 20% 31%)
OKLCH
oklch(55.2% 0.210 326.9)
HSV
hsv(299, 71%, 69%)
LAB
lab(44.78% 63.62 -41.32)
LCH
lch(44.78% 75.86 327.00)
CMYK
cmyk(2%, 71%, 0%, 31%)

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.

Rex
noun

Latin rex, king — adopted into English as the technical term for imperial purple-and-gold regalia. The rex color tradition refers to the Tyrian purple imperial robes of Roman emperors after Diocletian's 295 CE vestiarium reforms. Rex color refers to an imperial Roman purpura-dyed paludamentum cloak: a saturated, slightly cool deep violet with the matte finish of multi-bath Tyrian shellfish-dye on Roman imperial 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

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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.

#ad33b0
Original
#1960b3
Protanopia
#516fad
Deuteranopia
#b2476e
Tritanopia
#565656
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
5.42:1
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
3.88:1

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