Open Lupin
Open Lupin (#535679) is a true blue with an earthy character. It leans grounded and natural, the kind of color that plays well with wood, clay, linen, and warm neutrals. Its HSL profile (235°, 19%, 40%) places it in the muted 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 yellow. For something softer, pull in its analogous neighbors on either side of the wheel.
Etymology
Old English open, unobstructed — used as a color modifier since the eighteenth century for hues that read as airy or uncrowded. Open blue, open green: moderate saturation combined with optical spaciousness, the slight visual breath of a hue that doesn't crowd the surface it covers. Sits at the crisp-bucket center alongside clear.
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 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.