1 Combine red potatoes, Yukon Gold potatoes, purple potatoes, California Ripe olives, green onions and celery in a large mixing bowl and set aside.2 In a medium bowl, whisk together red wine vinegar, mustard and capers.3 Gradually whisk in olive oil, then season with salt, pepper and parsley.4 Pour dressing over potato mixture and toss until evenly coated.