Colour string format

A CSS named colour string or

  1. Common HTML color names. We support some 140 standard color names, based on the colors supported by the X Window system and most web browsers. color names are case insensitive. For example, red and Red both specify pure red.
  2. Hexadecimal color specifiers, given as #rgb or #rrggbb. For example, #ff0000 specifies pure red.
  3. RGB functions, given as rgb(red, green, blue) where the color values are integers in the range 0 to 255. Alternatively, the color values can be given as three percentages (0% to 100%). For example, rgb(255,0,0) and rgb(100%,0%,0%) both specify pure red.
  4. Hue-Saturation-Lightness (HSL) functions, given as hsl(hue, saturation%, lightness%) where hue is the color given as an angle between 0 and 360 (red=0, green=120, blue=240), saturation is a value between 0% and 100% (gray=0%, full color=100%), and lightness is a value between 0% and 100% (black=0%, normal=50%, white=100%). For example, hsl(0,100%,50%) is pure red.