Level Aerial
Level Aerial (#66D9F3) is a true cyan 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 (191°, 85%, 68%) 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 red. For something softer, pull in its analogous neighbors on either side of the wheel.
Etymology
Latin libella, small-balance / level-tool — sharing root with libra (balance). As a color modifier, level implies a clear-and-horizontal-true quality where the hue carries the visual register of gravity-perpendicular-and-perfectly-horizontal surface. Sits at the crisp-and-balanced end of the grid, parallel to plumb and flat in usage.
Of the air or sky — used in art-historical vocabulary for aerial perspective (the technique of using cooler, paler colors for distant elements to create depth). Aerial color refers to the saturated pale blue of distant mountains in clear atmosphere: a soft, slightly cool pale blue with the optical brightness of atmospheric Rayleigh scattering at distance.
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.