/* $DOC$
   $NAME$
      ft_Color2N()
   $CATEGORY$
      String
   $ONELINER$
      Returns the numeric complement of a Clipper color string
   $SYNTAX$
      ft_Color2N( <cColor> ) -> nValue
   $ARGUMENTS$
      <cColor> is a Clipper color string
   $RETURNS$
      The numeric complement of a color string or 0 if passed color
      is invalid.
   $DESCRIPTION$
      This function is useful when calling other functions that expect
      a numeric color parameter.  It is often more convenient to pass
      a converted color string than having to calculate or look up the
      corresponding number.
   $EXAMPLES$
      nColor := ft_Color2N( "gr+/b" )         // returns 30

      ft_SetAttr( 0, 0, 10, 10, nColor )
   $SEEALSO$
      ft_N2Color()
   $END$
 */