As per my dermatologist of a cousin, my skin (light, combination skin) creates the perfect conditions for post inflammatory hyperpigmentation. That being said, I've experimented with many natural home-made remedies over the years, and seem to have found a solution! Mix together equal parts of baking soda and manuka honey and form a paste. Apply once a day (I use it in the morning) for about 5-10 minutes and then rinse! It works wonders in evening out complexion and lightening any hyperpigmentation! I saw results within a week. Also most of you probably know picking at your pimples will cause/ worsen hyperpigmentation, SO DON'T DO IT! Although I don't pick at my pimples, I find that if I irritate my pimples in any way, I.e. exfoliate, this can also worsen hyperpigmentation.
Hope this helps!
Peace and Love