Deactivated Pieces can have an idle animation to better illustrate their power-up.
Ghost cell: Render borders only.
Bomb cell: Add a red and white flashing glowing square at the center, and display the red explosion border as the piece falls down
Drill cell: Make it completely red and flashing, without the white center of the bomb cell. Add flashing red borders on anything in the dropzone.
Tower cell: Make it completely white, and draw more rectangles offset in the falling direction to show that new blocks will be placed. Add flashing white borders on anything in the dropzone. In the idle animation, render border offsets
Deactivated Pieces can have an idle animation to better illustrate their power-up.