In a 400% oven, roast one can of corn with 1/2 teaspoons chili powder for 15 minutes, stirring twice. Set aside.
In a large bowl, mix mayonaisse, remaining chili powder, salt, pepper, and lime juice. Mix well. Add potatoes, peppers, olives, remaining can of corn, green onions, cilantro, and parsley. Mix well. Cover & chill.