I painted the muffler's heat shield black because I thought the bare sheet-metal look didn't look finished to me. I also thought it would be a closer match to the Kohler's black ducting.
The muffler from a side view.
For some reason, the engine wanted to run to the right side of the tractor so I tightened it down there. This caused the outlet to interfere with the grille. The exhaust pipe was also too low so I had to put some heat on it to move it up and to the right so it was centered in an opening. Notice that the original muffler had worn the grille slightly on the other side of the hole.