1. Combine the mayonnaise, juice concentrate, cider vinegar, mustard, celery seeds and zest in a small bowl. Mix until the dressing is well blended.
2. Combine the green cabbage, red cabbage, carrots and onion in a large bowl with a tight-fitting lid. Toss to mix well.
3. Add the dressing to the cabbage mixture. Stir until the vegetables are evenly coated with dressing. Cover tightly and refrigerate until ready to serve.
Tip: Shredding Cabbage
To easily shred cabbage, peel away the tough outer leaves from the head and discard. Cut the head into quarters and remove the core. Lay a quarter, flat side down, and cut crosswise into thin shreds. To save time, look for preshredded packaged coleslaw mix, available in the produce section.