Those dark spots are likely post-inflammatory hyperpigmentation, which is very common and naturally fades over time. To safely speed up healing, you can use over-the-counter topicals containing ingredients like Vitamin C, Niacinamide, Azelaic acid, or Glycolic acid. For more stubborn spots, a dermatologist can prescribe topical retinoids (such as tretinoin) or a short course of hydroquinone. Most importantly, apply a broad-spectrum sunscreen (SPF 30 or higher) daily, as UV rays can darken the spots and delay your progress. With consistent care, your skin will gradually clear up.