Leaves change color in autumn because the green pigment chlorophyll, which helps leaves make food from sunlight, breaks down as the days get shorter and the trees prepare for winter. When chlorophyll fades, other pigments in the leaves become visible: carotenoids show yellow and orange colors, and anthocyanins produce red hues. The combination of these pigments creates the vibrant fall foliage. Factors such as the length of daylight, temperature, and weather influence the intensity and timing of the color change. For instance, sunny days can increase red pigment production, while cold weather and soil conditions can also affect the colors seen.