Mature orange fruits change their peel color from green to orange during ripening. This degreening is an important process to determine the commercial quality of fruits. After reaching the full-ripe stage, some late season varieties such as Valencia turn their fruit peel color from orange to green. The regreened fruits are ripe inside, but cannot sell well due to their unripe-like appearance. The funded project aims to understand the molecular bases of this peel color development of citrus fruit, and to use the outcomes to develop efficient strategies to enhance color development and prevent regreening from happening.