I found those, but I don't get it. I know that each of the eight lines corresponds to a livery, but even if I enable two of them only one livery is avaliable in-game. Is texture naming important? I named them "goloco_sign_1" and I tried with "goloco_livery_1" aswell. I have multiple liveries in there but they don't seem to work.
Soo, this is actually pretty useful as I managed to add a new train engine. Although I have a question - how can I enable liveries for a new vehicle? Or that doesn't work yet?