How a Leaf Changes Color in Fall

Green plastids (figure 1): A green leaf is green because of the presence of a group of pigments known as chlorophylls. Minute structures called plastids contain the chlorophyll within the leaf. When these green pigments are abundant in the leaf's cells, as they are during the growing season, the chlorophylls' green color dominates and masks out the colors of any other pigments that may be present in the leaf. Thus the leaves of summer are characteristically green.