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Fathomless Heliotrope

#2a1b57
Notes

Fathomless Heliotrope (#2A1B57) is a deep indigo with an earthy character. It leans grounded and natural, the kind of color that plays well with wood, clay, linen, and warm neutrals. Its HSL profile (255°, 53%, 22%) 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
#2a1b57
RGB
rgb(42, 27, 87)
HSL
hsl(255, 53%, 22%)
HWB
hwb(255 11% 66%)
OKLCH
oklch(28.0% 0.103 289.6)
P3
color(display-p3 0.1559 0.1083 0.3282)
HSV
hsv(255, 69%, 34%)
LAB
lab(15.30% 24.27 -33.90)
LCH
lch(15.30% 41.70 305.60)
CMYK
cmyk(52%, 69%, 0%, 66%)

Etymology

Fathomless
adjective

Fathom (Old English fæthm, six-foot span used to measure water-depth) plus suffix -less. As a color modifier, fathomless implies a depth of saturation-and-darkness that resists the eye's attempt to gauge it. Sits at the deepest end of the deep-bucket grid, beyond ordinary measure of color-depth perception.

Heliotrope
noun

The genus Heliotropium — the cherry pie plant, named in Greek for its supposed habit of tracking the sun (heliotropism). The color refers to a fresh garden heliotrope cluster in late summer: a saturated, slightly red-shifted deep purple-blue with the matte finish of densely packed forget-me-not-style flowers. Cooler than mauve, warmer than indigo, with the perfumed weight of a flower whose vanilla-cherry scent fills a greenhouse.

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.

#2a1b57
Original
#002759
Protanopia
#002556
Deuteranopia
#1b2936
Tritanopia
#232323
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
15.08:1
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
1.39:1

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
##2A1B57
Display P3
Display P3
color(display-p3 0.1559 0.1083 0.3282)
P3 has subtle headroomOKLCH chroma 0.103

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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