In a large mixing bowl, toss together the rinsed and drained cannellini, kidney, and garbanzo beans. Make sure to get rid of as much liquid as possible so your salad isn’t too soupy. Then add in the finely chopped bell pepper, softened red onion (remember to drain it from soaking!), chopped celery, parsley, and rosemary. Give everything a good stir, making sure the beans and veggies are well combined. You want each bite to be colorful and inviting.