The first stages of the color change is when the leaves are green. When there green they are really healthy and are getting lots of health. When they change color. As soon as they start changing color the out side chemical that cover the leaf in the spring and summer is cracking witch lets a different chemical show off it's colors for a little while. these color's are orange and yellow. This is the start of the leaves death. The inside of the stem starts closing up. The stem is like the leafs feeding tube. it gives it all the things it can't get from the sun. The next step or color is red. This means that the stem is almost or completely closed. Because of this the orange and yellow colored chemical falls off and the last chemical that is red takes center stage. Soon even that chemical soon falls and the leaf turns brown and dies and falls to the ground.