In a small saucepan, combine the water and quinoa. Bring to boiling; reduce heat. Cover and simmer about 15 minutes or until water is absorbed. Remove from heat and set aside to cool completely.
Meanwhile, in a small bowl whisk together vinegar, oil, salt, and crushed red pepper. Stir in sweet pepper, carrots, zucchini and green onion. Add cooled quinoa; toss to coat. Serve immediately or cover and chill up to 24 hours before serving.