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Dense Annatto

#b31803
Notes

Dense Annatto (#B31803) is a true 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 (7°, 97%, 36%) places it in the highly saturated band at a mid 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
#b31803
RGB
rgb(179, 24, 3)
HSL
hsl(7, 97%, 36%)
HWB
hwb(7 1% 30%)
OKLCH
oklch(49.0% 0.189 30.9)
P3
color(display-p3 0.6440 0.1672 0.0945)
HSV
hsv(7, 98%, 70%)
LAB
lab(38.28% 58.05 50.79)
LCH
lch(38.28% 77.13 41.18)
CMYK
cmyk(0%, 87%, 98%, 30%)

Etymology

Dense
adjective

Latin dēnsus, thick / crowded — sharing root with English condense. As a color modifier, dense implies a saturated-and-tightly-packed quality where the hue carries maximum pigmentation per visual unit-of-area. Sits at the bold-and-saturated end of the grid, parallel to thick and concentrated in usage.

Annatto
noun

Bixa orellana, the tropical shrub whose seeds yield a red-orange dye used as food coloring (in cheese, butter, and margarine) and as body paint by the Caribbean and Central American indigenous peoples. The color refers to fresh annatto paste: a saturated, slightly orange red with the matte finish of plant-derived pigment. Warmer than vermillion, drier than tomato.

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.

#b31803
Original
#4f4500
Protanopia
#746600
Deuteranopia
#c60017
Tritanopia
#373737
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).
AAon White
6.89:1
The quick brown foxSample body text at normal size. The wcag minimum for body contrast is 4.5:1 (AA) or 7:1 (AAA).
AA Largeon Black
3.05:1

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
##B31803
Display P3
Display P3
color(display-p3 0.6440 0.1672 0.0945)
P3 has visible headroomOKLCH chroma 0.189

This color is chromatic enough that authoring it as P3 native (instead of clamping to sRGB) gives a perceptibly more saturated render on wide-gamut displays — modern Macs, iPhones, iPads, and most recent OLED laptops.

Related Colors

Canvas