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Imposing Rex

#330055
Notes

Imposing Rex (#330055) 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 (276°, 100%, 17%) places it in the highly saturated band at a dark lightness. Best used in small doses, like logos, CTAs, focus rings, or highlight text, where its saturation becomes a feature rather than noise. 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
#330055
RGB
rgb(51, 0, 85)
HSL
hsl(276, 100%, 17%)
HWB
hwb(276 0% 67%)
OKLCH
oklch(25.7% 0.134 304.8)
P3
color(display-p3 0.1801 0.0142 0.3195)
HSV
hsv(276, 100%, 33%)
LAB
lab(11.69% 38.76 -38.40)
LCH
lch(11.69% 54.55 315.27)
CMYK
cmyk(40%, 100%, 0%, 67%)

Etymology

Imposing
adjective

Latin impōnere, to place upon — present-participle of impose. As a color modifier, imposing implies a deep-and-massive-and-architectural quality, the dark cool-gray of Citadel-and-Cathedral monumental architecture against the sky. Sits at the deep-and-architectural end of the grid, parallel to towering and looming in scale.

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

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.

#330055
Original
#001e57
Protanopia
#001f54
Deuteranopia
#2c1b2e
Tritanopia
#111111
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
16.51:1
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
1.27:1

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
##330055
Display P3
Display P3
color(display-p3 0.1801 0.0142 0.3195)
P3 has subtle headroomOKLCH chroma 0.134

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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