WHISK to combine yogurt, honey, lemon juice (or vinegar), salt, pepper, and celery seed to make the dressing. Set aside.
ADD coleslaw vegetables to a mixing bowl. Toss in 1/4 cup of the cranberries and 2 Tablespoons of the sunflower seeds. Pour the dressing over the slaw and toss to coat completely. Transfer to a serving dish and scatter reserved cranberries and sunflower seeds over the top. Store leftovers, tightly lidded, in the refrigerator for up to 4 days.