CustomTransition black screen

[callmejm]

I using custom transition for my route transition. However, during the animation transition, the transition look black, not very nice, is there anyway to become white

import 'package:flutter/material.dart';
import 'package:flutter_modular/flutter_modular.dart';

CustomTransition get rightFadeRouteTransition => CustomTransition(
    transitionDuration: Duration(milliseconds: 300),
    transitionBuilder: (context, animation, secondaryAnimation, child){
      return SlideTransition(
        position: Tween<Offset>(begin: Offset(1.0, 0.0), end: Offset.zero).animate(animation),
        child: FadeTransition(
          opacity: Tween<double>(begin: 0.0, end: 1.0).animate(animation),
          child: FadeTransition(
            opacity: Tween<double>(begin: 1.0, end: 0.0).animate(secondaryAnimation),
            child: child,
          ),
        ),
      );
    },
  );

Video :

bandicam.2021-09-03.19-25-22-001.mp4

Screenshot: