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Sinister Hibiscadelphus

#3f0b18
Notes

Sinister Hibiscadelphus (#3F0B18) is a deep red 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 (345°, 70%, 15%) 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 teal. For something softer, pull in its analogous neighbors on either side of the wheel.

HEX
#3f0b18
RGB
rgb(63, 11, 24)
HSL
hsl(345, 70%, 15%)
HWB
hwb(345 4% 75%)
OKLCH
oklch(24.9% 0.080 10.6)
P3
color(display-p3 0.2251 0.0599 0.0960)
HSV
hsv(345, 83%, 25%)
LAB
lab(11.70% 25.93 5.83)
LCH
lch(11.70% 26.57 12.67)
CMYK
cmyk(0%, 83%, 62%, 75%)

Etymology

Sinister
adjective

Latin sinister, left / unlucky — used in classical-augury for the unfavorable left-hand-side of bird-flight omen-reading. As a color modifier, sinister implies a deep-and-foreboding-and-uncanny quality, the dark of Gothic-novel atmospheric-shadow and threatening-presence. Sits at the deep-and-uncanny end of the grid, parallel to foreboding and menacing in atmospheric register.

Hibiscadelphus
noun

A genus of Hawaiian endemic hibiscus relatives — H. distans and H. giffardianus — whose deep red flowers are pollinated by Hawaiian honeycreepers. Most species are now extinct or critically endangered. The color refers to the petal of a fresh H. distans bloom: a saturated, slightly cool deep red with the satin finish of mallow-family flower.

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.

#3f0b18
Original
#181818
Protanopia
#262317
Deuteranopia
#460210
Tritanopia
#171717
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
16.50:1
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
1.27:1

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
##3F0B18
Display P3
Display P3
color(display-p3 0.2251 0.0599 0.0960)
Inside sRGBOKLCH chroma 0.080

This color sits well within the sRGB cube. P3 and sRGB share the gray axis and most desaturated tones, so a P3 display renders this identically to an sRGB display.

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