Carotenoids are yellow or red pigments found in all photosynthesizing plants. With anthocyanins they contribute to autumn foliage shades when chlorophyll is lost. There are two types of carotenoids: the carotenes and xanthophylls. Carotenes are hydrocarbons (tetraterpenes), which are converted to vitamin A in the body. Xanthophylls are oxygenated derivatives of carotenes; they have no provitamin A activity.