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Senatorial Keep Crimson

#aa1823
Notes

Senatorial Keep Crimson (#AA1823) 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 (355°, 75%, 38%) 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
#aa1823
RGB
rgb(170, 24, 35)
HSL
hsl(355, 75%, 38%)
HWB
hwb(355 9% 33%)
OKLCH
oklch(47.5% 0.178 24.5)
P3
color(display-p3 0.6116 0.1608 0.1634)
HSV
hsv(355, 86%, 67%)
LAB
lab(36.60% 56.14 33.97)
LCH
lch(36.60% 65.62 31.18)
CMYK
cmyk(0%, 86%, 79%, 33%)

Etymology

Senatorial
adjective

Latin senātōrius, of the senator — adjectival suffix. As a color modifier, senatorial implies a saturated-and-aristocratic-and-Roman-Republic quality, the deep-rich color of Roman-Senate toga praetexta purple-bordered ceremonial-citizen-class livery. Sits at the bold-and-aristocratic end of the grid, parallel to patrician and imperial.

Keep
modifier

Old Norse keypa, to-keep. As a color modifier, keep implies a fortified-castle-keep-and-strongtower quality, the visual register of Norman-and-Welsh-castle-keep hand-built fortified-castle-keep-and-stronghold-tower medieval-and-Norman-castle architectural surfaces under medieval-Norman-and-Welsh castle-keep-and-stronghold light. Sits at the modifier-and-architecture end of the grid, parallel to tower and crenel 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.

#aa1823
Original
#494222
Protanopia
#6d611c
Deuteranopia
#bc001e
Tritanopia
#383838
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
7.33:1
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
2.86:1

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
##AA1823
Display P3
Display P3
color(display-p3 0.6116 0.1608 0.1634)
P3 has subtle headroomOKLCH chroma 0.178

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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