Minecraft now has fireworks, but those are a bit grandiose for a small celebration. XercaMod adds Confetti and Confetti Ball items for the purpose of celebration.
Confetti can be used directly, in which case the player will throw around a bunch of colorful particles. It can also be used to craft Confetti Balls together with Gunpowder. Confetti Ball can be thrown at a direction, and the ball will periodically burst with confetti during its flight. It can also be thrown by a dispenser.