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Plumbed Rough Ultramarine

#1b2880
Notes

Plumbed Rough Ultramarine (#1B2880) is a deep blue 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 (232°, 65%, 30%) 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 amber. For something softer, pull in its analogous neighbors on either side of the wheel.

HEX
#1b2880
RGB
rgb(27, 40, 128)
HSL
hsl(232, 65%, 30%)
HWB
hwb(232 11% 50%)
OKLCH
oklch(33.2% 0.147 269.5)
P3
color(display-p3 0.1165 0.1554 0.4826)
HSV
hsv(232, 79%, 50%)
LAB
lab(21.24% 28.14 -50.96)
LCH
lch(21.24% 58.21 298.91)
CMYK
cmyk(79%, 69%, 0%, 50%)

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.

Rough
modifier

Old English rūh, rough. As a color modifier, rough implies an unfinished-and-coarse quality, the visual register of unfinished-stone-and-burlap hand-quarried-and-unprocessed coarse-and-unfinished-textile-and-stone hand-quarried-and-coarse surfaces under hand-quarried-and-unfinished workshop-light. Sits at the modifier-and-texture end of the grid, parallel to hewn and bark in usage.

Ultramarine
noun

The pigment ground from lapis lazuli — the Afghan mineral imported through Venice in the late Middle Ages, more expensive by weight than gold during the Renaissance. The color refers to a freshly mixed ultramarine pigment in linseed oil: a saturated, slightly violet-shifted deep blue with the matte finish of micron-ground rock. Deeper than cobalt, cooler than royal, with the art-historical weight of the blue Vermeer reserved for Mary's robe.

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.

#1b2880
Original
#003883
Protanopia
#002e7e
Deuteranopia
#004050
Tritanopia
#2c2c2c
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
12.64:1
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
1.66:1

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
##1B2880
Display P3
Display P3
color(display-p3 0.1165 0.1554 0.4826)
P3 has subtle headroomOKLCH chroma 0.147

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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