def build_header_output
      output = []

      @header.each do |line|
        _data = []
        line.each do |h|
          _data << {:value => h, :color => @style[:header]}
        end
        output << _data
      end
      output
    end
def build_header_output
      output = []

      @header.each do |line|
        _data = []
        line.each do |h|
          _data << {:value => h, :color => @style[:header]}
        end
        output << _data
      end
      output
    end
Builds the header output for this table.

 Returns the color map and the header.