Color expressions
The hypertext.datatype provides a interface to obtain a specific color.The color can be a predefined color name or a RGB value string. The RGB value string is specified in the HTML form : `#RRGGBB', where `RR' is the red , `GG' is the green and `BB' is the blue portion of the RGB value specified in hexdecimal digits. For example the `#FF0000' and `Red' color expressions gets the same color : Red.

Here is the table of all predefined color names :

      Name          Color

      Black         #000000
      Green         #008000
      Silver        #C0C0C0
      Lime          #00FF00
      Gray          #808080
      Olive         #808000
      White         #FFFFFF
      Yellow        #FFFF00
      Maroon        #800000
      Navy          #000080
      Red           #FF0000
      Blue          #0000FF
      Purple        #800080
      Teal          #008080
      Fuchsia       #FF00FF
      Aqua          #00FFFF