title: Retain escape sequences and color when using sed
body: <p>I have output out of a test reporter that returns nicely colored results, and miscellaneous garbage I want to get rid of.  I tried using <code>sed</code> via:</p>
  
  <pre><code>karma start tests/karma.conf.js | sed 's|var.*browserify||'
  </code></pre>
  
  <p>...which removes the junk, but also kills the colored results.  How can I retain them?</p>
  
  <p>Here's an example of the raw output before sed:</p>
  
  <pre><code>^[[1A^[[2KERROR: 'Unhandled promise rejection' /var/folders/xs/wmmjbz4s6mdgcqynwn46qtmr0000gn/T/799ac09c665c85beb20f6d99be27c1cf.browserify?c65c8d7afc187ee2ed8307a171bc8e1511bfb40b:91625:48)
  </code></pre>