title: How to change the colour of the Switch thumb in React Native
body: <p>I have this <code>Switch</code> in my app, on iPhone it is displaying correctly, with a white thumb regardless of whether the switch is on or off. However, on web, when the switch is on, it is this blue colour, that is defined nowhere in my app. I cannot figure out how to override it.</p>
  <pre><code>&lt;Switch
         trackColor={{ false: colours.darkGrey, true: colours.primary }}
         ios_backgroundColor={colours.darkGrey}
         thumbColor={colours.white}
         onValueChange={toggleSwitch}
         value={notificationEnabled}
         style={styles.switch}
  /&gt;
  </code></pre>
  <p>The switch <code>switch</code> style:</p>
  <pre><code>switch: {
      transform: [{ scaleX: 0.7 }, { scaleY: 0.7 }],
    },
  </code></pre>
  <p>I am not too bothered that the shapes are not the same, but the colours should match.</p>
  <p><a href="https://i.stack.imgur.com/iaZG1.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/iaZG1.jpg" alt="enter image description here" /></a></p>
  <p><a href="https://i.stack.imgur.com/bqKc4.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/bqKc4.png" alt="enter image description here" /></a></p>