This is called PIH, post inflammatory hyperpigmentation and occurs in darker skin types frequently. I suggest a visit to a Dermatologist to discuss your options. Treatment should include a Retin A and hydroquinone. If indeed there are scars, that can be treated with the Infini.
Treatments for acne and acne scars
I would begin with once daily retinoids such as RR Retinoid Repair, Melapads, and Ematrix RF. Best, Dr. KaramanoukianLos Angeles