Praetorian Zǐ
Praetorian Zǐ (#9959D5) is a true indigo with a cool character. It leans cool, sitting on the blue, green, and violet side of the wheel. Quiet and dependable, a fit for product UI and data visualization. Its HSL profile (271°, 60%, 59%) 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
Latin praetōriānus, of the praetor — adjectival suffix, referring to the Roman-Imperial elite guard-cohorts. As a color modifier, praetorian implies a saturated-and-elite-and-imperial-guard quality, the deep-rich color of Roman-Praetorian-Guard elite-imperial-bodyguard scarlet-tunic-and-bronze-armor military-formation. Sits at the bold-and-formal end of the grid, parallel to spartan and imperial.
Chinese 紫, purple — the imperial court color of the Tang and Song dynasties, derived from Lithospermum erythrorhizon (gromwell) and overdyed with Polygonum tinctorium. Zǐ color refers to a Tang-dynasty imperial robe field: a saturated, slightly cool deep violet with the silk luster of multi-bath gromwell-root-and-indigo overdye on tussah silk. Cooler than zǐsè (formal deep purple).
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.