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Tomblike Arbor Ultramarine

#182a6b
Notes

Tomblike Arbor Ultramarine (#182A6B) 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 (227°, 63%, 26%) 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
#182a6b
RGB
rgb(24, 42, 107)
HSL
hsl(227, 63%, 26%)
HWB
hwb(227 9% 58%)
OKLCH
oklch(31.4% 0.116 267.5)
P3
color(display-p3 0.1099 0.1629 0.4040)
HSV
hsv(227, 78%, 42%)
LAB
lab(19.68% 18.01 -40.05)
LCH
lch(19.68% 43.92 294.22)
CMYK
cmyk(78%, 61%, 0%, 58%)

Etymology

Tomblike
adjective

Greek tymbos, tomb — adjectival suffix -like. As a color modifier, tomblike implies the deep-and-funereal-and-sepulchral quality of Etruscan-and-Egyptian rock-cut royal-tomb interiors, particularly the Valley-of-the-Kings and Cerveteri-necropolis hand-carved chamber-painting walls. Sits at the deep-and-funereal end of the grid, parallel to sepulchral and crypted.

Arbor
modifier

Latin arbor, tree-or-trunk. As a color modifier, arbor implies a Latin-tree-and-vine-arbor quality, the visual register of Pliny-Natural-History-and-Roman-villa-arbor hand-Latin-tree-and-vine-arbor Pliny-Natural-History-and-Roman-villa-arbor-and-pergola arbor-and-Latin-tree-and-vine-arbor surfaces under Pliny-Natural-History-and-Roman-villa-arbor-and-pergola Pompeii-and-Tuscan-pergola-and-grape-arbor leafy-shade-light. Sits at the modifier-and-Latin end of the grid, parallel to via and domus 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.

#182a6b
Original
#00346d
Protanopia
#002c6a
Deuteranopia
#003a46
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
13.27:1
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
1.58:1

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
##182A6B
Display P3
Display P3
color(display-p3 0.1099 0.1629 0.4040)
P3 has subtle headroomOKLCH chroma 0.116

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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