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Tough Uranus Crimson

#b51b27
Notes

Tough Uranus Crimson (#B51B27) is a true red with a vibrant character. It holds its own as a focal accent, carrying visual weight without tipping into neon territory. Its HSL profile (355°, 74%, 41%) places it in the balanced band at a mid lightness. It works across type, buttons, and borders, saturated enough to feel deliberate but balanced enough to not fight the rest of the palette. 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
#b51b27
RGB
rgb(181, 27, 39)
HSL
hsl(355, 74%, 41%)
HWB
hwb(355 11% 29%)
OKLCH
oklch(49.8% 0.186 24.3)
P3
color(display-p3 0.6515 0.1753 0.1798)
HSV
hsv(355, 85%, 71%)
LAB
lab(39.17% 58.69 35.04)
LCH
lch(39.17% 68.35 30.84)
CMYK
cmyk(0%, 85%, 78%, 29%)

Etymology

Tough
adjective

Old English tōh, firm / tenacious — sharing root with German zäh. As a color modifier, tough implies a saturated-and-resilient quality where the hue resists fading-and-modulation through its strong pigmentation. Sits at the bold-and-resilient end of the grid, parallel to rugged and hardy in usage.

Uranus
modifier

Greek Οὐρανός, primeval-sky-god-and-seventh-planet. As a color modifier, uranus implies a primeval-sky-god-and-pale-cyan-seventh-planet quality, the visual register of Greek-Uranus-and-Herschel-discovery hand-primeval-sky-god-and-pale-cyan-seventh-planet Greek-Uranus-and-Herschel-discovery-and-tilted-axis uranus-and-primeval-sky-god surfaces under Greek-Uranus-and-Herschel-discovery-and-tilted-axis 1781-Slough-discovery-and-side-rolling-planet pale-cyan-planet-light. Sits at the modifier-and-zodiac end of the grid, parallel to neptune and saturn in usage.

Crimson
noun

From the Old Spanish cremesin, itself from the Arabic qirmiz — the kermes scale insect, dried and ground into a brilliant carmine dye prized in the medieval Mediterranean. For centuries the most expensive red on a draper's shelf, reserved for cardinals, kings, and the cloth that gave English the word crimson. Cooler than scarlet, deeper than rose; the color of pomegranate seeds and a serious occasion.

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.

#b51b27
Original
#4f4726
Protanopia
#746820
Deuteranopia
#c80022
Tritanopia
#3d3d3d
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
6.66:1
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
3.15:1

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
##B51B27
Display P3
Display P3
color(display-p3 0.6515 0.1753 0.1798)
P3 has visible headroomOKLCH chroma 0.186

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

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