This research study examined longitudinal gender differences in computing outcomes among high school girls of color. Girls of color participating in a 3-year CS intervention demonstrated lower initial interest in computing and these gender differences persisted after one year of the intervention. Promising outcomes were revealed in year three of the intervention, where there were no gender differences in participation and completion of the AP CS A preparatory course. Yet, by college, girls of color were significantly less likely to persist in computing, suggesting unique challenges for girls of color. This paper was presented at the annual conference on Innovation and Technology in Computer Science education in Bologna, Italy on July 3-5, 2017, and won the “Best Paper” award.