All the no good, default, carpy, Auran Paintshed Template locos & cars are painted with Paintshed. It can not paint anything other than a few Paintshed Templates.
Reskining all the rest of locos and cars is done with technical programs other than Auran's, and Paintshed. It is not as easy as painting an HO Loco.
You have to master making masks, and detail layers. If you just fill paint a loco, you will wipe out all the rivots, doors, and details.