I want to make the confetti background so it looks like it is radiating out from the middle. I have tried using the scatter brush in both Photoshop and Illustrator but it looks a lot messier than this picture, and I can not just have two colours using the scatter brush. Could someone please tell me how to do it. (it has been suggested to me by a teacher that they would have done it manually)
You can do it manually by dragging objects while holding Alt key. This will create a duplicate. It's a lot faster than using Ctrl+C and Ctrl+V key combinations.
Another option is to create multiple circles in random distances from each other and add them as a new art brush. This is also a manual method, but it saves time.