TextField(
style: TextStyle(color: Colors.red),
decoration: InputDecoration(fillColor: Colors.orange, filled: true),
)
ThemeData(
// (...)
hintStyle: TextStyle(
color: Colors.grey, // <-- Change this
fontSize: null,
fontWeight: FontWeight.w400,
fontStyle: FontStyle.normal,
),
);
TextField(
style: TextStyle(color: Colors.white),
...
)