Effulgent Crepuscule
Effulgent Crepuscule (#9381EA) is a soft 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 (250°, 71%, 71%) places it in the balanced band at a light lightness. It works as a background wash, large-area fill, or soft illustration tone. Add a darker ink of the same hue when you need type over it. For a confident two-color system, pair it with its complementary yellow. For something softer, pull in its analogous neighbors on either side of the wheel.
Etymology
Latin effulgēns, shining-out — present-participle of effulgere, sharing root with fulgor (lightning). As a color modifier, effulgent implies a saturated-and-radiating-light-out quality, the bright color of Renaissance-Madonna halo-and-aureole gold-leaf-and-pigment emission. Sits at the bright-and-saturated end of the grid, parallel to resplendent and radiant in usage.
Latin crepusculum, twilight — adopted into French and English for the precise civil-twilight half-hour between sunset and nightfall. Crepuscule color refers to a clear-sky eastern anti-solar horizon at civil crepuscule (twelve minutes after sundown): a saturated, slightly cool deep blue-violet with the optical complexity of Rayleigh-scattered Belt of Venus light against the deepening Earth shadow.
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.
Moderately saturated colors gain a small bump in P3 — the difference is usually visible side-by-side on wide-gamut hardware but won't change the character of the color.