As I mentioned before, I can help you out with markings. There are a lot of possibilities. You can go the modern "Euro white" route, a retro cheat-line look, or something with a lot of body color.
Here's an old Pan-Am livery
These three were designs by some pro and amateur livery designers I modified by for my own ships.
These are some of my own designs:
Edited to add credits to livery designs!