title: Get JSON children of single node with random name in Groovy
body: <p>In Groovy (not Grails), I want to get the color of such an item:</p>
  
  <pre><code>{
      "8436": {
          "color": "red",
      }
  }
  </code></pre>
  
  <p>The "8436" number is dynamic, but there is always only one.</p>
  
  <p>I can't use JsonSlurper's <code>json.8436.color</code> syntax, because the number would be hard-coded.</p>
  
  <p>How to get the color?</p>