Bring a large pot of salted water to a boil. Add pasta and cook until al dente, about 8-10 minutes. Drain and rinse under cold water.

In a skillet, heat 2 tablespoons of olive oil over medium heat. Add shrimp and cook for 2-3 minutes until pink and opaque. Remove from heat.

In a bowl, whisk together 3 tablespoons of olive oil, lemon juice, and Dijon mustard until emulsified. Season with salt and pepper.

In a large bowl, combine cooled pasta, cooked shrimp, bell peppers, and red onion. Gently fold together.

Pour dressing over the mixture and toss gently to combine. Adjust seasoning if necessary.

Cover with plastic wrap and refrigerate for at least 30 minutes before serving.