First of all, thanks for the reply. Yes I apply the tracking data first to a null object and then parent the orb to it. For this test I did not actually used a green ball, because for now I dont have one, but for the real project I will paint it green. I used Roto Brush, because the result is almost the same. However, here is a picture of the markers:

The tracker tracks them good, but when i test with the orb, while moving my hand it slowly starts to run away from the required position. I adjust it manually at some frames, but the final result is not quite satisfying.