Fill a large pot with lightly salted water and bring to a boil over high heat. Stir in the orzo, and return to a boil. Cook the pasta uncovered, stirring occasionally, until the pasta has cooked through, but is still firm to the bite, about 10 minutes. Drain.
Place the drained orzo in a large salad bowl, and fold in the red pepper, yellow pepper, green onions, red onion, chickpeas, kidney beans, black beans, corn, cilantro, and salt and pepper to taste. Pour the lime juice and oil over the salad, toss to coat, and refrigerate at least 2 hours to chill before serving.