Hi, I can understand your concern for the problem dark spotted pimple marks on skin. This is due to activity of melanocytes which causes pigmentation. Melanocytes are the color producing cells of skin which causes deep pigmentation on aforesaid areas after healing of pimples and formation of scars. The most important part in treatment is by lightening agents such as Kojic acid or azelaic acid cream application which you can use under dermatological guidance. Hydroquinone can also be used but in my series of patients I prefer using Kojic acid or azelaic acid cream. You should continue with sun protection by all measures. Eat healthy diet containing lot of Vitamin A and Vitamin C. Do not try applying over the counter products as these can further aggravate the situation. Protect yourself form direct sunlight. Use a good sunscreen on exposed area for 2-3 times and drink plenty of liquids everyday. All the best.