A very magical and fun living room magic effect.  

A thick paper tube is unrolled showing that it contains nothing inside.

The tube is rolled again, and it is said that it is a very special one, since it is capable of changing the color of the things that pass through it.

Said this one takes a white ball, it is introduced by the superior part of the tube and when falling below it leaves blue color.

The same can be done several times turning the ball yellow, red and green.

After each color change you can show the inside of the rolled paper to show that there is nothing, and finally the same.

A rolled paper of a special material is supplied to last you all your life, and the set of all the balls to make the effect.