Rich Coast Ruby
Rich Coast Ruby (#A50524) is a deep red 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 (348°, 94%, 33%) 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 teal. For something softer, pull in its analogous neighbors on either side of the wheel.
Etymology
Old French riche, wealthy, abundant — applied to color since the medieval period for hues that read as plentiful in pigment. Rich red, rich brown: the implication is depth combined with saturation, a color that gives the eye more to absorb. Sits at the saturated mid-light corner of the engine's grid, slightly warmer than bold and deeper than vivid.
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.
From the Latin ruber — simply, red. The gemstone is a chromium-tinged corundum, harder than anything in nature except diamond, and so saturated that a fine Burmese pigeon's blood ruby at auction outpaces a comparable diamond by weight. The color borrows the gem's confidence: a clear, glassy red without the brown of garnet or the blue of crimson.
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.