When our son was diagnosed at 7 days old we were told that CAH, untreated, caused hyperpigmentation. I never asked for details (we began treating immediately) but what Peg said makes a lot of sense. At birth our son had a very olive complexion. I did think this was strange because I have very white skin (irish family) and my husband has scandanavian roots. By the time he was 6 months old our son much more closely matched our white complexions.