Sinewy Concord
Sinewy Concord (#66279C) is a true indigo with a jewel character. It carries the deep, saturated richness of a gemstone. Authoritative and slightly formal, it works well for type and heavy UI elements. Its HSL profile (272°, 60%, 38%) 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 lime. For something softer, pull in its analogous neighbors on either side of the wheel.
Etymology
Old English sinu, sinew — adjectival suffix -y. As a color modifier, sinewy implies a saturated-and-muscular-and-firm quality where the hue carries the lean-and-strong visual presence of a Roman-statue athletic figure. Sits at the bold-and-firm end of the grid, parallel to stalwart and rugged in usage.
Vitis labrusca, the Concord grape — bred in 1849 by Ephraim Wales Bull in Concord, Massachusetts, and the foundation of American grape juice and the kosher Manischewitz wine industry. The color refers to a ripe Concord grape on the vine: a saturated, slightly red-shifted very deep purple with the heavy bloom of waxy fruit surface. Cooler than wine, warmer than indigo, with the lunchbox-and-Welch's weight of a New England crop that changed an entire continent's beverage culture.
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.