"That was Berry Gordy's strategy, too -- taking his black singing groups and getting them to a white audience, " Covach says, referring to the Motown Records founder.

CNN: Dick Clark knew his business

While "Dark Girls" (www.officialdarkgirlsmovie.com) makes its way across the country, Duke and Berry are working on their next documentary, which will deal with light-skinned black women.

CNN: Dark skin is also a problem among African-Americans