The name says it all really. And who doesn't love rainbows and pizza?! You could make this with whatever veges you like really, so long as they're colourful! I used red onion, red cabbage, broccoli, corn, orange capsicum, cherry tomatoes, all piled on a foundation of tomato paste, cheese and oregano. I sprinkled with a little extra cheese afterwards too, but not too much - don't want to cover the colour!! Buon appetito!