def parse_fill_options(options={})
      return unless options[:bg_color]
      color = Color.new(:rgb=>options[:bg_color])
      dxf = options[:type] == :dxf
      color_key = dxf ? :bgColor : :fgColor
      pattern = PatternFill.new(:patternType =>:solid, color_key=>color)
      fill = Fill.new(pattern)
      dxf ? fill : fills << fill
    end
def parse_fill_options(options={})
      return unless options[:bg_color]
      color = Color.new(:rgb=>options[:bg_color])
      dxf = options[:type] == :dxf
      color_key = dxf ? :bgColor : :fgColor
      pattern = PatternFill.new(:patternType =>:solid, color_key=>color)
      fill = Fill.new(pattern)
      dxf ? fill : fills << fill
    end
parses add_style options for fills. If the options hash contains :type => :dxf we return a Fill object. If not, we return the index of the fill after being added to the fills collection.
 @note noop if :bg_color is not specified in options
 @option options [String] bg_color The rgb color to apply to the fill
 @return [Fill|Integer]