During spring and summer, leaves are green because of chlorophyll, famous for its role in production of carbohydrates and nourishment for plants and algae by consumption of water and carbon dioxide. Green color of abundant chlorophyll during the growing season dominates and masks out colors of other pigments like carotenoids. By change of season from summer to autumn, amount of chlorophyll in leaves dwindles, fading away its masking effect and giving chance to other pigments like carotenoids to display their colors.
Carotenoids, present in leaves the whole year around, provide colorations of yellow, brown, orange, and the many hues in between for the leaves of hickories, ash, maple, yellow poplar, aspen, birch, black cherry, sycamore, cottonwood, sassafras, alder and many others. Carotenoids are the dominant pigment in coloration of about 15-30% of tree species.
Anthocyanins produced towards the end of summer provide colorations of red and purple alone or deep orange, fiery red, bronze and many other bended colors alike in combination with carotenoids to leaves of maples, oaks, sourwood, sweetgums, dogwoods, tupelos, cherry trees, persimmons and many others. Anthocyanins are present in about 10% of tree species in temperate regions, although in certain areas, up to 70% of tree species may produce theses pigments.