Deluxe Parabox - In and Out boxes

Deluxe Parabox 

Effect: The magician opens a red box and reveals a blue box inside. Inside the blue box a red sponge ball can be seen. The red sponge ball is removed, now the red box is closed and put in the blue box (the box which was on the outside before is now located inside the other box).

The boxes are opened again, now inside the innermost box, a blue sponge ball is being found. Again the boxes are closed (now red box is on the outside again, and the blue box is inside). After opening the boxes for the last time, a yellow sponge ball is revealed.

Now the 2 boxes can be shown to be exactly the same size.

This is not over, the initial red sponge ball suddenly becomes larger in the hand of the magician.