Authoritative Aster
Authoritative Aster (#9A51DE) is a true indigo with a vibrant character. It holds its own as a focal accent, carrying visual weight without tipping into neon territory. Its HSL profile (271°, 68%, 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 auctōritāt-, authority — adjectival suffix -ive. As a color modifier, authoritative implies a saturated-and-formal-imperative quality where the hue carries decisional weight and institutional credibility. Sits at the bold-and-authoritative end of the grid, parallel to commanding and magisterial in usage.
The genus Aster — Greek for star — composite-family perennials whose blue-violet daisy-like flowers fill gardens in September and October when most other bloomers have finished. The color refers to a fresh New England aster (Symphyotrichum novae-angliae): a saturated, slightly violet-shifted blue with the matte finish of multi-rayed composite flowers. Cooler than veronica, warmer than larkspur, with the late-season weight of a flower that closes the perennial year.
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.