code: public void importColor(String colorNr, Color color) {
          RtfColor rtfColor = new RtfColor(this.rtfDoc, color);
          this.importColorMapping.put(colorNr, Integer.toString(rtfColor.getColorNumber()));
      }
docs: Imports a color value. The color number for the color defined
  by its red, green and blue values is determined and then the
  resulting mapping is added.
  
  @param colorNr The original color number.
  @param color The color to import.