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Authoritative Ptah Crimson

#ac1924
Notes

Authoritative Ptah Crimson (#AC1924) is a true red 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 (356°, 75%, 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
#ac1924
RGB
rgb(172, 25, 36)
HSL
hsl(356, 75%, 39%)
HWB
hwb(356 10% 33%)
OKLCH
oklch(48.0% 0.180 24.5)
HSV
hsv(356, 85%, 67%)
LAB
lab(37.11% 56.52 34.05)
LCH
lch(37.11% 65.98 31.07)
CMYK
cmyk(0%, 85%, 79%, 33%)

Etymology

Authoritative
adjective

Latin auctōritāt-, authority — adjectival suffix -ive. As a color modifier, authoritative implies a saturated-and-formal-imperative quality where the hue carries decisional weight and institutional credibility. Sits at the bold-and-authoritative end of the grid, parallel to commanding and magisterial in usage.

Ptah
modifier

Egyptian Ptah, Memphis-creator-god. As a color modifier, ptah implies a Memphis-creator-and-craftsman-god quality, the visual register of Egyptian-Ptah-and-Memphis-temple hand-Memphis-creator-and-craftsman-god Egyptian-Ptah-and-Memphis-temple-and-Apis-bull ptah-and-Memphis-creator-and-craftsman-god surfaces under Egyptian-Ptah-and-Memphis-temple-and-Apis-bull Memphis-Saqqara-and-craftsman-workshop creator-craftsman-light. Sits at the modifier-and-myth end of the grid, parallel to thoth and isis in usage.

Crimson
noun

From the Old Spanish cremesin, itself from the Arabic qirmiz — the kermes scale insect, dried and ground into a brilliant carmine dye prized in the medieval Mediterranean. For centuries the most expensive red on a draper's shelf, reserved for cardinals, kings, and the cloth that gave English the word crimson. Cooler than scarlet, deeper than rose; the color of pomegranate seeds and a serious occasion.

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.

#ac1924
Original
#4b4323
Protanopia
#6e621e
Deuteranopia
#be001f
Tritanopia
#393939
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
7.20:1
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
2.92:1

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