Bring a large pot of salted water to a boil. Add the pasta and cook until al dente, adding the corn in the last minute of cooking. Drain and rinse under cold water.
Whisk together the mayonnaise, sour cream, pickled jalapeños and brine, lime zest and juice, garlic, black pepper, and ½ teaspoon salt in a large bowl.
Add the baby bell peppers, scallions, tomatoes, and remaining ½ teaspoon salt to the bowl. Shake the pasta dry in the colander, then add to the bowl and toss. Sprinkle with the cilantro and parsley and toss again. Season with salt, if needed. Let sit for at least 30 minutes at room temperature or refrigerate for up to 6 hours.
