Hello Casey19425, welcome to the forum!!
There are a few people creating alternative lighting for some of the ships. By default, you cannot turn them on in the game. So it's not a feature in New Horizons, unfortunatly.
I think I saw one picture of a nicely lit titanic, but as far as I know, this was just a fake. A photoshopped screenshot.
Though I think our member RMS Gigantic is working on a 'mod' for the Titanic's lighting. But I do not think this was completed yet.
Regards,
Fred