Soft yellow foam practice balls have a hard center in them so the player can feel solid contact when they hit the ball.
The ball should be placed so the orange center is facing towards the face of the club. The orange spot has less resistance so it not only give a good visual point of contact, the player can hear and feel if they have hit the 'sweet spot'.
The perfect safety ball, the Short Flyte only goes about 20 yards before stalling out. Caution should still be used at close range because of the hard center but overall the Short Flyte provides optimal safety with a satisfying feel similar to hitting a Cayman ball.