code: def foreground(colour)
           style            = CharacterStyle.new
           style.foreground = colour
           root.colours << colour
           if block_given?
              apply(style) {|node| yield node}
           else
              apply(style)
           end
        end
docs: This method provides a short cut means of creating a foreground colour
   command node. The method accepts a block that will be passed a single
   parameter which will be a reference to the foreground colour node
   created. After the block is complete the foreground colour node is
   appended to the end of the child nodes on the object that the method
   is called against.
  
   ==== Parameters
   colour::  The foreground colour to be applied by the command.