Three types of pigments are involved in leaf color. - Chlorophyll is responsible for the green we see most of the year. It's necessary for photosynthesis which harnesses sunlight to make the sugars that plants need to grow. - Anthocyanins result in magnificent reds and are produced in the fall as a response to bright light and excess sugars within leaf cells. - Carotenoids produce yellow, orange, and brown and are present in the chloroplasts of leaf cells all year, but masked by chlorophyll. During autumn, night length increases, and chlorophyll production stops. The carotenoids and anthocyanins are unmasked and we see a brilliant display of colors.