I usually do pasta salad with the multi colored rotini, hunks of pepperoni, ham, chunks of white cheddar or swiss, black olives, cherry tomatoes, and toss the whole thing in Italian salad dressing.
Tricolor rotini, olives, tomatoes, green peppers and an oil and vinegar dressing. Since most Italian dressings would likely have cheese, you could just add some spices and make your own.
I make mine up. Pasta and veggies, whatever I have on hand. Carrots, peas and onions usually. Toss in Italian dressingn(dairy free for you). You could add bacon, mushrooms, asparagus, whatever you like.
Similar to others, I usually do tri color pasta, tomato, black olives, broccoli and chick peas with Italian dressing. I bet oil and vinegar + Italian seasoning would be great, too!
Eta: and salt and pepper. And maybe instead of Italian seasoning, whichever is your favorite blend?