Acne can cause red or brown discoloration and uneven skin contour. Usually multiple types of treatments are needed for maximum improvement. Patience is key since the full effect is often not seen for several months. techniques to improve large or numerous scars involve resurfacing the skin by intentionally traumatizing it in order to stimulate collagen production. This thickens the skin and shrinks the surface area of the scar, and color may be improved as well. The Cross technique uses a very concentrated TCA peel.