Students will learn that leaves lose their green color as the days grow shorter and the weather becomes colder and that as the green disappears other colors become visible, while still new colors are created.
Leaves change color in the fall because the days grow shorter with fewer hours of sunlight.
When there's not enough sunlight, the green chlorophyll cells in plants stop making food and break down. As they break down, chlorophyll cells lose their green color, but other colors that have been in the leaf all along then can be seen. Still other new colors are formed through new chemical reactions that become possible once the chlorophyll is gone. When the Little Green Food Factories Shut Down. All leaves have some yellow pigment in them, and many have red tones as well.