Need a Part but dont know the name of it..

I have a 2011 Reddish Copper Stryker but some of the accessories I want to add to the bike are midnight. With that said I am looking for a part to see if I would like the look.. On my rear fender I have a chrome accessory on each side. They run just behind the seat towards the rear. I am looking to change them out to the black ones. Not sure what they are called but also not sure how to get a black set of them.. Any help would be great. Thank you