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Central Umbra

#230503
Notes

Central Umbra (#230503) 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 (4°, 84%, 7%) 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 cyan. For something softer, pull in its analogous neighbors on either side of the wheel.

HEX
#230503
RGB
rgb(35, 5, 3)
HSL
hsl(4, 84%, 7%)
HWB
hwb(4 1% 86%)
OKLCH
oklch(17.4% 0.054 29.8)
P3
color(display-p3 0.1236 0.0262 0.0158)
HSV
hsv(4, 91%, 14%)
LAB
lab(4.27% 12.89 5.40)
LCH
lch(4.27% 13.98 22.72)
CMYK
cmyk(0%, 86%, 91%, 86%)

Etymology

Central
adjective

Latin centrālis, central — adjectival suffix -al. As a color modifier, central implies a neutral-and-central-and-balanced quality where the hue carries the visual register of Mid-Century-Modern and Bauhaus central-and-balanced-and-grounded foundational-design fundamental-element. Sits at the neutral-and-foundational end of the grid, parallel to core and grounded in usage.

Umbra
noun

Latin umbra, shadow — adopted into astronomy as the technical term for the deep-shadow inner cone of an eclipse shadow, where the occulting body completely blocks the light source. Umbra color refers to a total solar eclipse ground-level observer's path of totality darkness: a saturated, slightly cool deep black with the optical complexity of total-solar-eclipse atmospheric scattering against a shadow-cone-occluded sun-disk.

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.

#230503
Original
#0d0b03
Protanopia
#151102
Deuteranopia
#280105
Tritanopia
#0b0b0b
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
19.19:1
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
1.09:1

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
##230503
Display P3
Display P3
color(display-p3 0.1236 0.0262 0.0158)
Inside sRGBOKLCH chroma 0.054

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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