Leaves change color in the fall due to the breakdown of chlorophyll, the green pigment responsible for photosynthesis. As the days get shorter and temperatures drop, trees begin to prepare for winter by gradually stopping the production of chlorophyll. This reveals other pigments in the leaves, such as carotenoids (which create yellow, orange, and brown hues) and anthocyanins (which produce red and purple colors), leading to the beautiful array of colors seen in the autumn season.
