Certain Gemini Mulberry
Certain Gemini Mulberry (#651695) is a deep 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 (277°, 74%, 34%) places it in the balanced band at a dark lightness. It works well as a headline, icon, or deep background in an otherwise light layout, pairing cleanly with cream, bone, and warm neutrals. 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
Latin certus, fixed / sure — sharing root with English concern and certify. As a color modifier, certain implies a saturated-and-unambiguous quality where the hue declares its character without hesitation. Sits at the bold-and-confident end of the grid, parallel to assured and decisive in usage.
Latin gemini, twins-of-the-zodiac. As a color modifier, gemini implies a twins-and-air-sign-and-Mercury-ruled-mutable-air quality, the visual register of Castor-and-Pollux-Gemini-twins hand-twins-and-air-sign-and-Mercury-ruled-mutable-air Castor-and-Pollux-Gemini-twins-and-Argonaut-twins gemini-and-twins-and-air-sign surfaces under Castor-and-Pollux-Gemini-twins-and-Argonaut-twins late-spring-and-May-and-June mutable-air-sign-light. Sits at the modifier-and-zodiac end of the grid, parallel to castor and pollux in usage.
The genus Morus — the white mulberry (M. alba) feeds silkworms; the black mulberry (M. nigra) bears the deep purple fruit that stains everything it touches. The color refers to a ripe black mulberry: a saturated, slightly red-shifted very deep purple with the slight juiciness of a compound fruit. Cooler than wine, warmer than indigo, with the agricultural weight of a tree that supported the entire Chinese silk industry for two thousand years.
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.