Bring a large pot of lightly salted water to a boil. Add shells and cook, stirring occasionally, until tender yet firm to the bite, about 9 minutes. Drain.
Mix sour cream, mayonnaise, lemon juice, honey mustard, dill, salt, and pepper together in a bowl until creamy.
Transfer cooked pasta to a large bowl. Add sour cream mixture, crabmeat, bell peppers, and green onions. Toss until well combined, then cover and chill for 1 to 2 hours before serving.