That's regular chrome, maybe black chrome was an option. Here's the best pic I could find of the black chrome:

 

hmm, inteesting, I have literally never seen an S4 with that on. Pretty cool if it was an option

 

Every s4 I've seen has regular chrome, interesting

i stand corrected, every s4 in my area that's for sale has the dark chrome stuff, cool...

does it just snap off? i wouldn't mind getting the dark trim for my 2.8 which has the chrome..

 

I've seen one s4 with regular chrome and one with that black chrome, strange