Boil the orzo in a pot of salted water according to package directions until tender. Drain thoroughly and allow it to cool completely. In a spacious mixing bowl, combine the olive oil, orange juice, cucumbers, tomatoes, bell pepper, red onion, parsley, and oregano. Incorporate the cooled orzo into the mixture and toss well. Season with salt to taste. Gently fold in the crumbled feta and olives, if desired. Serve chilled or at room temperature.