This colorful pie, loaded with every color of the rainbow, takes veggie pizza to a whole new level. It’s a great way to put your farmers market haul to work, and makes firing up the oven totally worth it. Think of these colorful toppings as suggestions. There’s so much room for experimenting and really making this your own creation. Do you have a soft spot for blue potatoes or purple cabbage? Consider swapping either one in, in place of the red onion.