I also have a 2015 same color LT 4x4 and decided to go with these after searching long and hard. Decided the Fuel Ammo Anthricite in 17" (wanting to keep mileage and towing capabilities as close to factory) will go well with the tungsten grey paint. I also have black powder coated yitamotors running boards. https://www.tirerack.com/wheels/WheelCloseUpServlet?target=wheelCloseUp&wheelMake=Fuel+Off-Road&wheelModel=Ammo&wheelFinish=Anthracite+w%2FBlack+Ring
https://www.ebay.com/itm/YITAMOTOR-Running-Boards-for-07-19-Silverado-2500-HD-Crew-Cab-6-Bar-Side-Steps/254774173467?_trkparms=aid%3D1110012%26algo%3DSPLICE.SOIPOST%26ao%3D1%26asc%3D20201210111451%26meid%3D618e5fe0756540d09ffa68d1b82efaf1%26pid%3D101196%26rk%3D6%26rkt%3D12%26mehot%3Dpf%26sd%3D283845922416%26itm%3D254774173467%26pmt%3D1%26noa%3D0%26pg%3D2047675%26algv%3DPromotedSellersOtherItemsV2WithMLRv3&_trksid=p2047675.c101196.m2219&autorefresh=true