Cook the orzo pasta according to package instructions. Drain and let cool.
In a large bowl, combine the cooled orzo, red and yellow bell peppers, carrots, cucumber, red onion, feta cheese, and parsley.
In a small bowl, whisk together olive oil, red wine vinegar, Dijon mustard, salt, and pepper.
Pour the dressing over the salad and toss to combine.
Serve chilled or at room temperature.