There are roughly three hundred named colors that start with the letter A — drawn from CSS/W3C named colors, brand and paint palettes, Pantone and RAL naming, and traditional Japanese, Indian and European color vocabularies, alongside widely-circulated public color databases. Where a primary source defines an official value, the entry says so; other hex values are best read as common digital approximations. The list is deduplicated by hex value.

Azure is among the most historically significant: its name descends — through Old French, Medieval Latin, Arabic and Persian — from lapis lazuli, the blue stone mined at Sar-i-Sang in Afghanistan since antiquity. (The English word "azure" itself is medieval, entering the language in the 14th century; the prized blue pigment ground from lapis is ultramarine.) Alice Blue, Amber, Amethyst and Aquamarine are also among the most-recognized A-colors in modern usage.

It was named after Alice Roosevelt Longworth, the eldest daughter of U.S. President Theodore Roosevelt. The pale-blue gown she wore at her January 3, 1902 White House debutante ball — said by contemporary accounts to match her blue-gray eyes — made the shade a national fashion sensation. It is not one of the sixteen original HTML/VGA basic color keywords; it entered the web platform later, via the X11 color list and SVG 1.0, and was formally adopted in CSS Color Module Level 3.

Aqua (#00FFFF) is identical to Cyan in sRGB — pure, electric blue-green at maximum saturation. Aquamarine (#7FFFD4) is paler and slightly green-shifted, named after the gemstone, and is a softer, more pastel hue.

For CSS-named colors, yes — the W3C specification fixes the exact sRGB values. For Pantone, RAL, and Crayola, hex values are approximate conversions from those brands' proprietary swatch books, which are defined under specific lighting conditions. Different sources occasionally disagree by a few digits; this page uses the most widely-cited public values.

Individual color values themselves generally aren't copyrightable, so the hues shown here can usually be reused freely. Brand and institutional identities are different: names, logos, and uses that imply affiliation may be restricted by trademark or brand-identity rules (Airbnb Red, Arsenal Red, etc.). Using a similar hue in your own design is generally fine; using it to imply a brand association is not.