您可以在CircularProgressIndicator（）中使用类似这样的多色。

import 'package:flutter/material.dart';
 import 'package:flutter_screenutil/flutter_screenutil.dart';
 import 'package:mis/app_extensions.dart';

class LoadingIndicator extends StatefulWidget {
const LoadingIndicator({ Key? key,}) : super(key: key);

@override
State<LoadingIndicator> createState() =>_LoadingIndicatorState();
}

class _LoadingIndicatorState extends State<LoadingIndicator>
with SingleTickerProviderStateMixin {
late AnimationController animationController;

@override
void initState() {
animationController =
    AnimationController(vsync: this, duration: Duration(seconds: 1));
animationController.repeat();
super.initState();
}

@override
void dispose() {
animationController.dispose();
super.dispose();
}

@override
Widget build(BuildContext context) {
return Container(
  alignment: Alignment.center,
  child: CircularProgressIndicator(
    valueColor: animationController
        .drive(ColorTween(begin: AppColors.blueTop, end: AppColors.red)),
  ),
);
}
}