Decorously Czarny
Decorously Czarny (#0A0319) 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 (259°, 79%, 5%) 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 lime. For something softer, pull in its analogous neighbors on either side of the wheel.
Etymology
Latin decōrōsus, seemly / proper — adverbial-and-adjectival suffix -ly. As a color modifier, decorously implies a neutral-and-formal-and-proper quality where the hue carries the visual register of Edwardian-and-Victorian propriety-and-decorum-respecting coordinated formal-color-decision. Sits at the neutral-and-traditional end of the grid, parallel to properly and appropriately in usage.
Polish for black — derived from the Slavic root čьrnъ, sharing root with Russian chyornyy. Czarny color refers to a Polish-Catholic priest's czarny funerary cassock: a saturated, slightly cool deep black with the matte finish of multi-bath iron-and-tannin-mordant dye on woven Polish wool. The Slavic color tradition distinguishes czarny smolisty (pitch-black) from czarny granatowy (very dark navy).
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 sits well within the sRGB cube. P3 and sRGB share the gray axis and most desaturated tones, so a P3 display renders this identically to an sRGB display.