Similar to hsl() notation, but with an added alpha (opacity) value.
hsla(240, 100%, 50%, 0) /* transparent */
hsla(240, 100%, 50%, 0.5) /* half-translucent blue */
hsla(240, 100%, 50%, 1) /* fully opaque blue */
Syntax
hsla(<hue>, <saturation>%, <lightness>%, <a...