Leaves change there colors in the fall because the maple trees, oak trees, birch trees, and poplar trees, all have thin leaves that aren't so tough. The reason why the evergreen tree leaves don't fall of every winter is because they have a waxy coating to protect the leaves from freezing in the winter. This whole process is just because of some special chemicals.
Green: The leaves stay green through Summer and Spring because of the chemical, chlorophyll.
Red: The leaves turn red because of the chemical, anthocyanins.
Orange: The leaves turn orange because of the chemical, xanthophyll.
Yellow: The leaves turn yellow because of the chemical, carotene.
Brown: The leaves turn brown because they are the waste products trapped in the leaves.
Pine Leaves: The pine leaves are different then the other leaves. They don't fall off at all. They don't fall off because they have a waxy coating that keeps them from freezing.
Green: The leaves stay green through Summer and Spring because of the chemical, chlorophyll.
Red: The leaves turn red because of the chemical, anthocyanins.
Orange: The leaves turn orange because of the chemical, xanthophyll.
Yellow: The leaves turn yellow because of the chemical, carotene.
Brown: The leaves turn brown because they are the waste products trapped in the leaves.
Pine Leaves: The pine leaves are different then the other leaves. They don't fall off at all. They don't fall off because they have a waxy coating that keeps them from freezing.