Pasta Salad with Shrimp, Peppers, and Olives

3/4 cup chopped plum tomato

1/2 cup chopped red bell pepper

1/2 cup chopped yellow bell pepper

1/3 cup chopped green onions

2 tablespoons fresh lemon juice

1 tablespoon chopped pitted kalamata olives

1 tablespoon olive oil

1 1/2 teaspoons chopped fresh or 1/2 teaspoon dried thyme

1/2 teaspoon white pepper

1/4 teaspoon dried oregano

3/4 pound cooked medium shrimp, peeled and deveined

1 garlic clove, minced

1/2 cup (2 ounces) crumbled feta cheese

1 tablespoon chopped fresh parsley