You will definitely need to use a sunscreen lotion and follow the package directions for how often to reapply.

http://www.acne.org/spf.html

The Regimen was designed as an acne treatment but does not directly address dark marks or scarring. Many people confuse these issues so I will give you some links.

http://www.acne.org/faq.html#redmarks

and

http://www.acne.org/ethnic-skin.html#hyperpigmentation

and

http://www.acne.org/scars.php

Hope that helps!