Scratch it with a Scotch-Brite pad to make it a matte finish. Use about 2 million small circular rubs with the pad all up and down the rod. Be sure it's the real Scotch-Brite and you'll want one of the finer grit pads.

Black will get scratched up and look like crap before long. The Scotch-Brite method of finish is easily corrected if it gets shiny from rubbing on something.