title: Add new data into PHP JSON string
body: <p>I have $data as JSON encoded data and I have this string:</p>
  
  <pre><code>$new_data = "color:'red'";
  </code></pre>
  
  <p>that needs to be added to $data so that I can read it from it as a json string.</p>
  
  <p>How can I achieve this ?</p>