Earlier, we set ourselves the goal of changing the color of the Cylinder when it is hit by a projectile. To do so, we need to change the Actor's Material. A Material is an asset that can be added to an Actor's Mesh (which defines the physical shape of the Actor) in order to create its look. You can think of a Material as a coat of paint applied on top of an Actor's Mesh or shape. Since an Actor's Material determines its color, one method for changing the color of an Actor is to replace its Material with a Material of a different color. To do this, let's first create a Material of our own. It will make an Actor appear red.