Heavy Coast Tanzanite
Heavy Coast Tanzanite (#780869) is a deep violet 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 (308°, 88%, 25%) places it in the highly saturated band at a dark 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 green. For something softer, pull in its analogous neighbors on either side of the wheel.
Etymology
Old English hefig, weighty — cognate with heave. Used as a color modifier since at least the seventeenth century to indicate weight in saturation as much as value: heavy with pigment, heavy-bodied. In the engine's adjective grid, heavy sits alongside deep and plush in the dark-and-saturated quadrant. Closer to a fabric description than a pure value word.
Latin costa, rib / side. As a color modifier, coast implies a sea-edge-and-salt-air quality, the visual register of Atlantic-and-Mediterranean shoreline fishing-village stone-and-lime-stucco-and-sun-bleached-textile working-life surfaces against the working-and-receiving sea. Sits at the modifier-and-place end of the grid, parallel to shore and strand in usage.
A blue-violet variety of zoisite — discovered in 1967 in a single small area of northern Tanzania near Mount Kilimanjaro and marketed by Tiffany & Co. shortly after. The color refers to a faceted tanzanite cut to maximize its strong pleochroism: a saturated, slightly violet-shifted deep blue-purple with the gem's signature internal life. Cooler than amethyst, warmer than iolite, with the gem-trade specificity of a stone that occurs in exactly one place on Earth.
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.