def has_background_color? color=:any
      bg_color = flattened[:background_color] ? flattened[:background_color].to_s.downcase : nil

      if color != :any and bg_color
        return bg_color == color.to_s.downcase
      elsif bg_color
        return !(flattened[:background_color].downcase=='#ffffff' or flattened[:background_color]=='#000000')
      else
        return false
      end
    end
def has_background_color? color=:any
      bg_color = flattened[:background_color] ? flattened[:background_color].to_s.downcase : nil

      if color != :any and bg_color
        return bg_color == color.to_s.downcase
      elsif bg_color
        return !(flattened[:background_color].downcase=='#ffffff' or flattened[:background_color]=='#000000')
      else
        return false
      end
    end
Initializes Workbook::Format with a hash. The keys in the Hash are intended to closely mimick the CSS-style options (see above)

 @param [Workbook::Format, Hash] options (e.g. :background, :color, :background_color, :font_weight (integer or css-type labels)
 @return [String] the name of the format, default: nil
 Does the current format feature a background *color*? (not black or white or transparant).