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Imposing Flit Ultramarine

#15317d
Notes

Imposing Flit Ultramarine (#15317D) is a deep azure 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 (224°, 71%, 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 amber. For something softer, pull in its analogous neighbors on either side of the wheel.

HEX
#15317d
RGB
rgb(21, 49, 125)
HSL
hsl(224, 71%, 29%)
HWB
hwb(224 8% 51%)
OKLCH
oklch(34.5% 0.133 264.7)
P3
color(display-p3 0.1099 0.1896 0.4721)
HSV
hsv(224, 83%, 49%)
LAB
lab(23.12% 20.06 -45.99)
LCH
lch(23.12% 50.17 293.56)
CMYK
cmyk(83%, 61%, 0%, 51%)

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.

Flit
modifier

Old Norse flytja, to-move-or-shift. As a color modifier, flit implies a quick-darting-and-light-winged quality, the visual register of swallow-and-warbler-flit hand-quick-darting-and-light-winged swallow-and-warbler-and-darting-finch flitted-and-quick-darting-and-light-winged surfaces under swallow-and-warbler-and-darting-finch summer-eaves-and-hedgerow-and-meadow-edge dappled-flight-light. Sits at the modifier-and-mood end of the grid, parallel to hover and flutter 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.

#15317d
Original
#003c80
Protanopia
#00327c
Deuteranopia
#004452
Tritanopia
#313131
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
11.88:1
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
1.77:1

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
##15317D
Display P3
Display P3
color(display-p3 0.1099 0.1896 0.4721)
P3 has subtle headroomOKLCH chroma 0.133

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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