Flutter – How to change TextField hint color?

You can do with hintStyle: in InputDecoration

TextField(
        style: TextStyle(fontSize: 20),
        decoration: InputDecoration(
          hintText: "Password",
          hintStyle: TextStyle(fontSize: 20.0, color: Colors.redAccent),
          border: OutlineInputBorder(
            borderSide: BorderSide(
              color: Colors.teal,
            ),
          ),
          prefixIcon: const Icon(
            Icons.security,
            color: Colors.white,
          ),
        ),
      ),