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Plumbed Sumi

#3a1f73
Notes

Plumbed Sumi (#3A1F73) is a deep indigo with a cool character. It leans cool, sitting on the blue, green, and violet side of the wheel. Quiet and dependable, a fit for product UI and data visualization. Its HSL profile (259°, 58%, 29%) 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
#3a1f73
RGB
rgb(58, 31, 115)
HSL
hsl(259, 58%, 29%)
HWB
hwb(259 12% 55%)
OKLCH
oklch(33.0% 0.135 292.0)
HSV
hsv(259, 73%, 45%)
LAB
lab(20.51% 34.01 -43.77)
LCH
lch(20.51% 55.42 307.85)
CMYK
cmyk(50%, 73%, 0%, 55%)

Etymology

Plumbed
adjective

Latin plumbum, lead — past-participle of plumb (to measure depth with a lead-weighted line). As a color modifier, plumbed implies a deep-and-cool quality measured-to-its-fullest-depth, the dark cool-gray of lead-and-pewter metallic surfaces. Sits at the deep-and-cool end of the grid, parallel to fathomless with metallic register.

Sumi
noun

Japanese ink stick, made from soot of pine resin or sesame oil mixed with animal-glue binder, used in sumi-e brush painting and shodō calligraphy. Although nominally black, undiluted sumi on rice paper carries a deep blue-violet undertone. Sumi color refers to a heavily-loaded sumi brushstroke: a saturated, slightly cool deep blue-violet with the matte finish of pine-soot ink on absorbent washi.

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.

#3a1f73
Original
#003376
Protanopia
#003071
Deuteranopia
#283446
Tritanopia
#2b2b2b
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
12.94:1
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
1.62:1

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