Not sure this is the right category to ask this, but here it is anyway.
According to Styles and Themes | Android Developers, the Theme.AppCompat.Light Android theme is the light theme.
However, on a brand new Ionic Vue app, all the HTML5 native dialogs ( alert, prompt, date and time pickers) in the WebView get rendered with the dark theme by default. (Green text on dark grey background)
By looking at the Android files I noticed the main activity uses android:theme="@style/AppTheme.NoActionBarLaunch"
which just extends AppTheme.NoActionBar which has Theme.AppCompat.NoActionBar as the parent.
In Theme.AppCompat.NoActionBar the dialogs have a dark grey background. To get a light background Theme.AppCompat.Light.NoActionBar needs to be used.
Not sure if this is done on purpose, but if anyone else wants light dialogs out of the box this is how I fixed it.
Before, brand new app:
After:
