def colorize(indexes, params = {}, &block)
      [*indexes].each do |index|
        index = parse_index(index)
        if index
          obj = extract_component(params, &block)
          component[:colorizers][index] = obj
        else
          colorize_null params, &block
        end
      end
    end
def colorize(indexes, params = {}, &block)
      [*indexes].each do |index|
        index = parse_index(index)
        if index
          obj = extract_component(params, &block)
          component[:colorizers][index] = obj
        else
          colorize_null params, &block
        end
      end
    end
Sets a component to colorize a column.

 The component must respond to +call+ with the column value (or row if used with
 #using_row) as the arguments and return a color or +nil+ if default color should be
 used. A block can also be used.


 === Args

 +indexes+::
   The column indexes or its aliases
 +params+::
   A hash with params in case a block is not given:
     - :using defines the component to use
     - :with defines the color to use (to use the same color for all columns)

 === Example

   table.colorize :description, :with => :magenta
   table.colorize([:value, :total]) { |value| :red if value < 0 }