Make salad: Mix collard leaves, kale, romaine, cabbage, pear, onion, orange bell pepper, avocado, carrot, tomatoes, walnuts, and raisins together in a large bowl.

Make dressing: Combine olive oil, vinegar, honey, oregano, chili powder, Dijon mustard, garlic, salt, and black pepper in a glass jar with a lid. Cover with a lid and shake vigorously until dressing is well mixed.

Pour dressing over salad; toss to coat.