The treatments for red/pink spots are different than the ones for brown spots.
The flat pink reddish spots that remain on your skin after the pimples heal, are actually enlarged blood capillaries. In most cases these pink spots will fade in a few weeks to months without special treatment.
If these pink spots do not fade, they can be treated with lasers or Intense Pulse light (IPL). These lasers, used by many Dermatologists. produce intense pulses of light that absorbed in these small capillaries. The heat produced by the laser, coagulates these capillaries eliminating the pink spots.
Treatment for brown post acne spots is usually quite easy and will include over the counter whitening creams or stronger prescription whitening creams that contain hydroquinone. The more persistent brown spots can be treated by special superficial chemical peels (Jessner’s solution) or by the same lasers or IPLs used to treat red spots. These lasers destruct the excess melanin in the skin fading the brown spots.