Bring a large pot of water up to a boil, add some salt and cook the green beans until tender and bright green, 2-3 minutes. After 2-3 minutes of cooking, immediately drain the beans in a colander and submerge them under cold running water to stop the cooking process and help them keep their bright color. Once the beans are nice and cold, remove them from the running water, gently dry them off with a paper towel and reserve them in a large bowl.
To make the dressing, juice the two unsliced oranges into a large mixing bowl. Add the honey, Dijon mustard and red wine vinegar to the orange juice. Slowly whisk in the EVOO in a slow and steady stream and season the dressing with salt and pepper.
Add the reserved beans, peppers, onions and orange rounds to the bowl and toss to coat with the dressing.