def add(options={})
      value_objects << Cfvo.new(:type => options[:type] || :min, :val => options[:val] || 0)
      colors << Color.new(:rgb => options[:color] || "FF000000")
      {:cfvo => value_objects.last, :color => colors.last}
    end
def add(options={})
      value_objects << Cfvo.new(:type => options[:type] || :min, :val => options[:val] || 0)
      colors << Color.new(:rgb => options[:color] || "FF000000")
      {:cfvo => value_objects.last, :color => colors.last}
    end
creates a new ColorScale object.
 @see Cfvo
 @see Color
 @example
     color_scale = Axlsx::ColorScale.new({:type => :num, :val => 0.55, :color => 'fff7696c'})
 adds a new cfvo / color pair to the color scale and returns a hash containing
 a reference to the newly created cfvo and color objects so you can alter the default properties.
 @return [Hash] a hash with :cfvo and :color keys referencing the newly added objects.
 @param [Hash] options options for the new cfvo and color objects
 @option [Symbol] type The type of cfvo you to add
 @option [Any] val The value of the cfvo to add
 @option [String] The rgb color for the cfvo