In a large pot or Dutch oven, heat the olive oil over medium heat.
Add the onion and garlic and saut for 2-3 minutes, until softened.
Add the carrots, celery, zucchini, yellow squash, and red bell pepper and saut for 5-7 minutes, until the vegetables are tender.
Add the diced tomatoes, broth, thyme, salt, and pepper and bring the soup to a boil.
Reduce the heat and simmer the soup for 10-15 minutes.
Add the macaroni and continue to simmer for an additional 8-10 minutes, or until the macaroni is cooked.
Ladle the soup into bowls and serve hot.
