Hello, I understand your concern for black scar like marks left after the acne. If is quite common to find such kind of marks due to a simple phenomenon known as Post- inflammatory hype pigmentation. It is due to over-activity of color producing cells which cause the pigmentation. I suggest you to do sun protection so that these spots should nt darken more. In my patients I suggest them to apply a cream containing kojic acid with arbutin in it at night time. Apply the cream in thinnest possible amount so that it should not be visible to the naked eye. You can take further guidance from your treating dermatologist. All the best.