I consider scallops one of the original paint graphics, along with pinstriping. If you remember cartoons of the '50s, they often used a bunch of parallel lines called "speed lines" to show something moving fast!

If you want an early look, keep the colors basic...white, black red yellow blue.

For a more modern look add faded tips with another color, and some pinstripes.

For a classy look, metalflake would be nice, and you could still add the faded tips and striping.....or some spider webs between them.....or.....

If you are talking about your yellow truck, I would think about white, silver, or whatever your interior color is.