Sturdy Lupin
Sturdy Lupin (#566FF4) is a true blue with a neon character. It sits at the high-saturation edge of its family. Use it sparingly, as signage, accent, or highlight against darker surfaces. Its HSL profile (231°, 88%, 65%) 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 amber. For something softer, pull in its analogous neighbors on either side of the wheel.
Etymology
Old French estourdi, stunned, reckless — drifted in English to mean robust, well-built. Used as a color modifier since the seventeenth century for hues that read as durable and unfussy — the working browns of saddle leather, the working greens of pasture wool. Sits in the bold-and-warm corner alongside robust and solid.
The genus Lupinus — North American and European legumes whose tall blue-violet flower spikes appear in alpine meadows and cottage borders. The Latin lupus, wolf, references the old (incorrect) belief that the plant depleted soil. The color refers to a fresh blue lupin spike: a saturated, slightly violet-shifted blue with the matte finish of stacked pea-family flowers. Cooler than larkspur, warmer than wisteria, with the high-meadow weight of a perennial that tolerates poor soil.
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 exploreHarmonies
Accessibility
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.
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.
Wide gamut
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.
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.