How do I Select one random object from a set in a layout?

I am working on creating a brick breaker style game, and I would like to make it so that each time a brick is destroyed there is a small chance of one other brick remaining changing to a different colour.

I only want one brick to change, and only occur each time a brick is destroyed.

I have tried using an Array, but I cannot figure out how to store the UIDs in the Array and then succesfully pull a random UID from that array and apply a new animation/frame to the object tied to that UID.

Any help would be greatly appreciated, quite new to all of this so my know how is fairly limited

You can do something like this:

Brick On Destroy 
 Wait 0
	System Pick All Brick
	System Pick Random Brick
		Brick Set color.....

You're my hero lol. Been screwing around with Arrays for something so simple