Plants - Plant biology - Autumn leaf color
Why do leaves change color in autumn?
Correct!
In spring and summer, a leaf contains a great deal of chlorophyll. This green pigment supports photosynthesis and masks other pigments such as yellow and orange carotenoids. In autumn, shorter days and changing conditions reduce photosynthesis, and chlorophyll breaks down. The yellow and orange pigments that were already present then become visible. Some plants also produce red or purple anthocyanins.
Source: U.S. Forest Service
