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Robust Cardinalflower

#cb3651
Notes

Robust Cardinalflower (#CB3651) is a true red with a warm character. It leans warm, pulling light toward red, orange, and yellow. Naturally inviting, it suits editorial and hospitality contexts. Its HSL profile (349°, 59%, 50%) 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 teal. For something softer, pull in its analogous neighbors on either side of the wheel.

HEX
#cb3651
RGB
rgb(203, 54, 81)
HSL
hsl(349, 59%, 50%)
HWB
hwb(349 21% 20%)
OKLCH
oklch(56.5% 0.185 15.4)
HSV
hsv(349, 73%, 80%)
LAB
lab(46.89% 59.38 19.99)
LCH
lch(46.89% 62.65 18.60)
CMYK
cmyk(0%, 73%, 60%, 20%)

Etymology

Robust
adjective

From the Latin robustus, of oak — implying strength combined with substance. As a color modifier, robust describes saturation combined with body: a robust burgundy, a robust olive. Sits in the bold-and-warm corner alongside strong and solid, with the slightly textural implication of a color that has substance behind the pigment.

Cardinalflower
noun

Lobelia cardinalis, the North American wildflower whose tall spikes of brilliant red flowers are the favored nectar source of ruby-throated hummingbirds in late summer. The color refers to a fresh cardinalflower bloom: a saturated, slightly orange red with the satin finish of long-spurred bee-pollinated flower. Brighter than scarlet.

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

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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.

#cb3651
Original
#5e5b51
Protanopia
#847a4d
Deuteranopia
#de0041
Tritanopia
#585858
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
5.02:1
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
4.19:1

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