In a medium saucepan, combine vinegar, honey, water, salt, and pepper. Bring to a boil, then simmer for 2 minutes.
In a large bowl, combine all beans and sliced onion.
Pour the warm dressing over the beans and onions. Mix gently to coat.
Cover and refrigerate at least 8 hours or overnight, stirring occasionally.
Serve chilled. Stir before serving.