Sterile Aisle Lazuli
Sterile Aisle Lazuli (#3864A3) is a true azure 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 (215°, 49%, 43%) 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 amber. For something softer, pull in its analogous neighbors on either side of the wheel.
Etymology
Latin sterilis, barren / not-fertile — sharing root with Greek steiros (barren). As a color modifier, sterile implies a clear-and-medical-clean-and-stripped quality, the crisp color of operating-theater surgical-environment white-and-stainless-steel surfaces. Sits at the crisp-and-clean end of the grid, parallel to sanitary and hygienic in usage.
Old French aisile, side-aisle. As a color modifier, aisle implies a side-aisle-flanking-nave quality, the visual register of Romanesque-and-Gothic-cathedral hand-built side-aisle-and-arcade column-and-arch flanking-the-nave architectural surfaces under Gothic-and-Romanesque side-aisle filtered light. Sits at the modifier-and-architecture end of the grid, parallel to nave and apse in usage.
Passerina amoena, the lazuli bunting — a North American songbird whose males display saturated deep-blue plumage with white wing bars and chestnut breasts. Named for the gemstone (lapis lazuli) the bird's plumage resembles. The color refers to a male lazuli bunting in breeding plumage: a saturated, slightly cool deep blue.
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.
Moderately saturated colors gain a small bump in P3 — the difference is usually visible side-by-side on wide-gamut hardware but won't change the character of the color.