
In a small bowl, whisk mustard, salt, sugar, honey, pineapple juice, vinegar, mayonnaise, sour cream, pepper, onion powder, and celery seeds. Then refrigerate until ready to use (up to a day ahead).
In a salad bowl, mix green and purple cabbage, shredded carrots, and pineapple tidbits.
Pour the coleslaw dressing over the cabbage mixture and mix well, starting with a small amount at a time until thoroughly combined.
Season with salt and pepper. Keep refrigerated until ready to use.