title: Flutter web has wrong colors in browser on Android with dark theme
body: <p>Opera Touch browser on Android is applying dark theme styling on websites created with Flutter, for devices with dark theme enabled.</p>
  <p>Seems like all <code>Text</code> widgets are changed, e.g. from black to white, but backgrounds for widgets like <code>Container</code> are not always changed. This makes the webpage unreadable.</p>
  <p>Is there a way to disable this in Flutter, like not let browsers apply their own theme?</p>
  <p>I tried to force light theme, but that didn't help.</p>
  <pre><code>MaterialApp(
    title: webpageTitle,
    themeMode: ThemeMode.light,
    darkTheme: ThemeData(brightness: Brightness.light)
    ...
  )
  </code></pre>