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
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