Why do leaves change color?

DENVER (KDVR) -- Fall is a wonderfully colorful time thanks to the changing leaves around us. But why do leaves change color each fall?Leaves have chlorophyll in them that give them green pigment during the warmer months. In the fall, when the temperatures get cooler and the sun angle changes, the tree's chlorophyll starts to break down.When is peak fall foliage?Eventually, the green color disappears and other colors become visible. The leaf color depends on the pigment present in the leaf.
(KDV