Why do leaves turn yellow, red and orange in the fall?

Answer by  snale (16)

The reason that the leaves change color is because in the fall the chlorophil runs out of the leaves, allowing us to see the real color of the leaf which is usually tinted green. Orange and yellow are the leaf year round but red indicates food left in the leaf and brown is waste trapped in the leaf.

Answer by  sodman (28)

Chlorophyll fades away when triggered by short days and cool temperatures. Carotenoids, which is in the leaves all along but hidden by the green chlorophyll, then appear as yellow and orange. When warm days produce sugars that can not flow to the branches and trunk during cool nights, anthocyanins are produced.

Answer by  shego (255)

Leaves change color in the Fall because they are slowly dying. When leaves are green, they are new and alive. As the weather turns colder, warm weather trees begin to lose their foliage. It is a life cycle in progress.

Answer by  Anonymous

How do the properties of the new substances compare with the properties of the original substances after a chemical change takes place?