Why do leaves change color in the fall?

Leaves change because sunny days get shorter. The green fades away. Then yellow, orange, and red show. The tree lets leaves fall down.

In fall, days get shorter and colder. Leaves stop making the green food they use in warm months. When the green goes away, other colors show, like taking off a green blanket and finding yellow and orange underneath. Then the tree drops the leaves to rest through winter.

Leaves look green because of chlorophyll, a green stuff that helps leaves use sunlight to make food. In fall, there is less daylight and cooler air, so trees stop making as much chlorophyll. The green breaks down, and hidden yellow and orange colors show. Some leaves also make red colors from sugar trapped inside. Fun fact: the brightest reds often happen after sunny fall days and chilly, but not freezing, nights.