If it is faded from heat and use you might have to respray it to really get it lookin' good again. Since I don't know what kind of paint it is and don't have it on mine I can't really try anything I have to see. If it started out shiny like the one in the photo you might try some ultra fine polish (3M Foam Pad Polish & Swirl Mark Remover) on a spot that doesn't show to see what happens. If it started out flat, polish could ruin it.
Maybe someone that has the same pipes and knows what'll work will check in soon.