In this recipe's demo, you will change the background color of the app each second. You will create a list of five colors, and each second you will change the background color of a Container widget that fills the whole screen.
The color information will be emitted from a stream of data. The main screen will need to listen to the Stream to get the current Color, and update the background accordingly.
While changing a color isn't exactly something that strictly requires a stream, the principles explained here may apply to more complex scenarios, including getting flows of data from a web service. For instance, you could write a chat app, which updates the content based on what users write in real time, or an app that shows stock prices in real time.
