Pellucid Aether
Pellucid Aether (#1770AC) is a true azure 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 (204°, 76%, 38%) places it in the highly saturated band at a mid 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 orange. For something softer, pull in its analogous neighbors on either side of the wheel.
Etymology
Latin pellūcidus, transparent — derived from per-lūcēre (to shine through). As a color modifier, pellucid implies a clear-and-translucent quality where the hue reads with optical clarity and minimal turbidity. Sits at the crisp-and-clear end of the grid, parallel to lucid and translucent in usage.
The classical Greek upper atmosphere — the saturated deep blue beyond the lower air, where the gods dwelt in Homeric and Hesiodic cosmology. The fifth Aristotelian element. Aether color refers to the upper-atmospheric blue at high-altitude horizon: a saturated, slightly cool very deep blue with the optical depth of long atmospheric column.
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.