What are the common causes of cast iron discoloration and how can it be prevented or remedied?

Common causes of cast iron discoloration include exposure to high heat, acidic foods, and improper seasoning or maintenance. To prevent discoloration, avoid cooking highly acidic foods for prolonged periods, season the cast iron properly, and clean it gently with mild soap and water. To remedy discoloration, scrub the surface with a mixture of salt and oil, or use a commercial cast iron cleaner.