Hardy Sloop Indigo
Hardy Sloop Indigo (#1D5EE8) is a true azure with a vibrant character. It holds its own as a focal accent, carrying visual weight without tipping into neon territory. Its HSL profile (221°, 82%, 51%) 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 hardi, bold / brave — past-participle of hardir (to make brave). As a color modifier, hardy implies a saturated-and-cold-resistant quality, the deep-rich color of Scandinavian-and-Russian boreal-forest-and-tundra outdoor-clothing. Sits at the bold-and-resilient end of the grid, parallel to tough and resilient.
Dutch sloep, single-masted-vessel. As a color modifier, sloop implies a single-masted-fore-and-aft-rigged-vessel quality, the visual register of American-and-Dutch-sloop hand-built single-masted-fore-and-aft-rigged sloop-and-cutter maritime-architecture surfaces under American-and-Dutch sloop-and-cutter maritime sailing light. Sits at the modifier-and-nautical end of the grid, parallel to skiff and hull in usage.
Indigofera tinctoria, the South Asian legume whose leaves yield the deep blue dye that has clothed humanity for at least four thousand years — Egyptian linen, Mayan textile, the slave-grown plantations of Carolina. The color refers to a freshly indigo-dyed cotton thread: a saturated, slightly violet-shifted deep blue with the slight lustre of a fiber surface oxidized in air. Deeper than cobalt, cooler than royal.
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.