colors
Back to gallery

Severe Heliotrope

#370e6a
Notes

Severe Heliotrope (#370E6A) is a deep indigo 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 (267°, 77%, 24%) places it in the highly saturated band at a dark lightness. Best used in small doses, like logos, CTAs, focus rings, or highlight text, where its saturation becomes a feature rather than noise. 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
#370e6a
RGB
rgb(55, 14, 106)
HSL
hsl(267, 77%, 24%)
HWB
hwb(267 5% 58%)
OKLCH
oklch(29.7% 0.143 296.4)
P3
color(display-p3 0.1971 0.0658 0.3990)
HSV
hsv(267, 87%, 42%)
LAB
lab(16.34% 39.23 -44.76)
LCH
lch(16.34% 59.52 311.23)
CMYK
cmyk(48%, 87%, 0%, 58%)

Etymology

Severe
adjective

Latin sevērus, strict / serious. As a color modifier, severe implies a deep-and-uncompromising-formal quality, the dark plain-textile color of Cistercian and Calvinist anti-decorative interior aesthetic. Sits at the deep-and-formal end of the grid, parallel to austere and stern in tone.

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.

#370e6a
Original
#00296c
Protanopia
#002768
Deuteranopia
#29293d
Tritanopia
#1d1d1d
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
14.65:1
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
1.43:1

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
##370E6A
Display P3
Display P3
color(display-p3 0.1971 0.0658 0.3990)
P3 has subtle headroomOKLCH chroma 0.143

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.

Related Colors

Canvas