Flutter: ColorTween Example

A quick example that demonstrates how to use the ColorTween widget in Flutter to create a smooth transition between two colors.

Preview

This small app displays a circle whose background color changes continuously from blue to amber and from amber to blue.

The complete code:

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

void main() {
  runApp(const MyApp());
}

class MyApp extends StatelessWidget {
  const MyApp({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return const MaterialApp(
      // Remove the debug banner
      debugShowCheckedModeBanner: false,
      title: 'Kindacode.com',
      home: HomePage(),
    );
  }
}

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

  @override
  State<HomePage> createState() => _HomePageState();
}

class _HomePageState extends State<HomePage> with TickerProviderStateMixin {
  // animation controller
  late AnimationController _controller;
  // animation color
  late Animation<Color?> _color;

  @override
  void initState() {
    super.initState();
    _controller = AnimationController(
      duration: const Duration(seconds: 5),
      vsync: this,
    )..repeat(reverse: true);

    // color tween
    _color =
        ColorTween(begin: Colors.blue, end: Colors.amber).animate(_controller);
  }

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

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Container(
        alignment: Alignment.center,
        color: Colors.black87,
        child: AnimatedBuilder(
          animation: _color,
          builder: (BuildContext _, Widget? __) {
            return Container(
              width: 300,
              height: 300,
              decoration:
                  BoxDecoration(color: _color.value, shape: BoxShape.circle),
            );
          },
        ),
      ),
    );
  }
}

Further reading:

• Using AnimatedIcon in Flutter
• Flutter TweenAnimationBuilder Examples
• Flutter: FadeTransition example
• Flutter & SQLite: CRUD Example
• How to create Blur Effects in Flutter
• Flutter: 5 Ways to Add a Drop Shadow to a Widget

You can also take a tour around our Flutter topic page and Dart topic page to see the latest tutorials and examples.