American Girl Barbie Dolls were issued from 1965 to 1966
The American Girl Barbie, named for her hair style, represents the peak of Barbie's glamour and elegance. The American Girl Barbie and her 1600 series ensembles are the most glamorous and the most coveted by collectors and are among the most valuable. These dolls came with low color and high color.  The American Girl also came in another hair style called a "Side Part" which is coveted by all collectors.

Color Magic Barbie Dolls were issued in 1966
Color Magic Barbie came with either Golden Blonde or Midnight Black hair that changed to either Scarlet Flame or Ruby Red when the enclosed solution was applied. These are the hardest to find and some of the most expensive vintage Barbie dolls.  Some Color Magic Barbie dolls are considered "high color" with very vivid makeup. These are generally more valuable. Mattel did produce a highly collectable Platinum White Color Magic that was only a promotional doll and is very rare.