title: Color of cell array in Ruby RTF gem
body: <p>I have an exercise to do as homework. I have to make a rtf file with colored array. I'm using a rtf gem to do this. Here is documentation of that gem <a href="http://ruby-rtf.rubyforge.org/docs/" rel="nofollow">http://ruby-rtf.rubyforge.org/docs/</a>.
  I have written something like this while ago. But coloring using "backgroung method" doesn't affect on file.</p>
  
  <pre><code>require 'rubygems'
  require 'rtf'
  include RTF
  
  document = Document.new(Font.new(Font::ROMAN, 'Times New ROMAN'))
  
  red = Colour.new(255,0,0)
  green = Colour.new(0,255,0)
  
  array = document.table(2, 2)
  array[0][0].background(red) &lt;&lt; "text"
  array[0][1] &lt;&lt; "text"
  array[1][0] &lt;&lt; "text"
  array[1][1].background(green) &lt;&lt; "text"
  
  File.open('document.rtf', "w") {|f| f.write(document.to_rtf)}
  </code></pre>
  
  <p>Any ideas what Could I do?</p>