In autumn, chlorophyll is degraded in the leaves of deciduous trees. why do the leaves change color to shades of yellow, orange, or red?

Due to the coloring pigment Anthocyanins.

Explanation:

It is the Anthocyanins which is the factor behind the yellow , orange and red color of leaves.

During autumn season, the leaves of a plant stop making food. As a result of this the chlorophyll with in the leaves of such plants start degrading. Since the chlorophyll gives green color to the leaves, thus once this green pigment is degraded leaves no more remain green. They first convert to yellow color , then orange and finally red due to the coloring pigment "Anthocyanins"

In some cases even the stems start changing color due to high level of Anthocyanins

answer; i believe its echoic memory,it is believed to last three to four seconds; good luck