In a former life I did color and graphics for a major powersports manufacture.
I loath the last 20 years or so of RV graphics, the swoops, waves
Then at least in the case of our big foot are applied with medium quality vinyl that doesn't even match when it comes to seams.
So, heres the rub
If you change the style too much you run into the old more simple single or double stripe design, that lasted for something like 40 years of RV.
Your best bet.
Start hitting up the interwebs and start building a collection of graphic treatments you like, there's a lot of web based sources you can use to hold this information places pinterest and tumblr and flickr
Dont limit yourself to just RV's look at boats, look at advertising, look at city buses (don't laugh some of them have decent graphic stripes, it's just the colors suck) Also fire apparatus often have cool graphic shapes that are more traditional then the swoopy curvy stuff, without look too retro.
The big thing(you will see what I did there in just a second)
Is that you are trying to break up the massive amount of space the side of the camper is, so stuff that runs horizontal often looks better then graphics that are more vertical, graphics heavy in the center make the overall mass of the camper look smaller.
After a little bit you will start to see what you like. then that needs to be translated into 3D.
Printing out a photo of your camper and using tracing paper and colored markers is a quick way to see what a color and pattern will look like.
Keep in mind that the sides of a bigfoot
are not as straight as you might think and that longer runs of straight graphics get hare to look good the longer they are.
There are thousands of color available in pre-colored vinyl
Just make sure you get some that is rated for long outdoor UV exposure.
Like at least 5 if not 10 year stuff.
I like 3M Scotchcal brand products, but they are expensive.
Another option is a wrap, you can even have them wrapped in a solid color, including white and colored metallics.
For me personally, I like the running bigfoot
graphic, but he needs a little tune up and a little modernization. and I don't mind the 2000 vintage sunset over waves our camper has. It also needs a tune up, the design is very much stuck in the 80s and 90s. But that stretched clotted blood red and rose silver swoosh not so much.
I really dig the totally functional look of all white rigs, especially when trimmed out with black, tinted windows
and dark anodized aluminum trim
I tend to like more classic graphics solid straight stripes and metallic neutral silvers, whites or maybe some retro colors like you would see on stock pick-up from the 1950-1970's
I will most likely use some Scotchlite, (like Scotchcal it's made by 3M but it's reflective) to do something kind of fun.
Good luck and take some photos when you finish it, I'd love to see what you ended up with.