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Imposing Sugilite

#631e89
Notes

Imposing Sugilite (#631E89) 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°, 64%, 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
#631e89
RGB
rgb(99, 30, 137)
HSL
hsl(279, 64%, 33%)
HWB
hwb(279 12% 46%)
OKLCH
oklch(39.9% 0.169 310.1)
P3
color(display-p3 0.3574 0.1367 0.5178)
HSV
hsv(279, 78%, 54%)
LAB
lab(27.81% 48.17 -45.56)
LCH
lch(27.81% 66.30 316.60)
CMYK
cmyk(28%, 78%, 0%, 46%)

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.

Sugilite
noun

A manganese-bearing cyclosilicate gem first described in 1944, with major sources in South Africa's Wessels Mine. The color refers to a polished sugilite cabochon: a saturated, slightly red-shifted deep purple with the matte finish of opaque mineral. Cooler than amethyst, warmer than tanzanite, with the gem-trade rarity of a stone produced commercially from one principal mine and priced accordingly.

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.

#631e89
Original
#003f8c
Protanopia
#004387
Deuteranopia
#5e3853
Tritanopia
#343434
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
10.11:1
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
##631E89
Display P3
Display P3
color(display-p3 0.3574 0.1367 0.5178)
P3 has subtle headroomOKLCH chroma 0.169

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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