Fast Facts: Fall Color

Do you love how the leaves change color each fall? The pigments that create the bright yellows and oranges that make the fall landscape so pretty have been there since the leaves formed in spring. We just don’t see them until fall because they've just been masked by chlorophyll, the pigment that gives leaves their familiar green color.

(Photo by Chad Merda)

The colors in the leaves are all the result of pigments, and different pigments produce different colors. Chlorophyll is responsible for the green color in leaves, while xanthophylls create yellows, carotenoids make oranges and anthocyanins make reds. In spring and summer, leaves produce a lot of chlorophyll because it is necessary for photosynthesis. The other pigments are also present, but not in the same quantities as chlorophyll, so the other colors are not expressed in the leaves.

When the amount of daylight each day begins to get shorter as summer turns to fall, it signals the leaves to stop making chlorophyll. When this happens, the green color fades away and those other pigments are expressed in the familiar yellows, oranges and reds we love to see each fall.