1. CSS3 Colors

    Method of describing colors using Hue, Saturation and Lightness (hsl()) rather than just RGB, as well as allowing alpha-transparency with rgba() and hsla().

  2. types: <color>: `hsl()` (hsl color model)

  3. types: <color>: `hsl()` (hsl color model): alpha parameter

  4. types: <color>: `hsl()` (hsl color model): mix `<percentage>` and `<number>` in parameters

  5. types: <color>: `hsl()` (hsl color model): relative hsl colors

  6. types: <color>: `hsl()` (hsl color model): space-separated parameters