Tova Williams Examines Dyed Samples (IMAGE) North Carolina State University Caption Tova Williams, a Ph.D. student at North Carolina State University, does research relevant to the 75 percent of American women who color their hair and the stylists who apply it. Williams received a National Science Foundation Graduate Research Fellowship to study principles of sustainable hair color design. Credit North Carolina State University, Becky Kirkland Usage Restrictions Credit: North Carolina State University License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.