Plasti-dip
eazy-e and dre literally rapped for rails......yeah you could probably blast some eazy-e and DRE and they might turn black? worked for most white kids i know.....
But seriously i think you mean wrap, just go to a decal shop and they could sell you some stock vinyl to wrap em yourself...
Anodize. Theres multiple hardnesses.
My painted polaris rails are all chipped up from **** getting kicked up from the scratchers.
Anodizing will not chip.