Meanwhile I removed all the non generic files from my sgsm folder and I have my good old ball back

Unfortunately, I still don't know which file was responsible for the ball in the game.
Thanks for the ball, it looks better than mine.
EDIT: Well, the topic may be closed now as I put my ball.fsh file in the main sgsm folder and it overwrote my previous ball. Previously I put it in sgsm/common folder and it didn't work. Now I know what to do to have new balls in game.