The brick at the top fires the "Special effect" with Firerelay events and only Firerelay.
The disk however, itself, sets the pixel color without the firerelay.
The clearscreen uses the "Special Effect" to clear the screen.
1. TopBrick fires a relay down
2. 4 top pixel blocks catch the relay, displaying certain colors though delays from white, to black.
3. The brick fires a relay down to the next set of pixel blocks, and step 2 and 3 are replayed untill their is no bricks to fire relays at.