By Craig Koplien Special to Published Oct 22, 2013 at 12:15 PM

Ever wonder why leaves change from green to orange, yellow and red in the fall?

The color of leaves depends on the chemicals within them. More specifically, it depends on the most abundant chemical in a leaf at any point in time.

During spring and summer, leaves are filled with chlorophyll, carotene and xanthophyll. Chlorophyll, the chemical vital to the food-making photosynthesis process, is green and the most abundant chemical during the warm season. The orange and yellow colors of carotene and xanthophyll get overwhelmed by the more abundant green chlorophyll.

In fall, trees slow the production of chlorophyll and eventually stop the production of it completely. This causes the green color of the leaf to fade and allows the yellow and orange colors of the carotene and xanthophyll to show through.

Some leaves turn red in fall. This is due to the chemical anthocyanin. It is produced only in certain leaves and only during fall when chlorophyll production slows.

Craig Koplien Special to

Craig is a meteorologist who was born and raised in Pewaukee. After getting a degree in Meteorology from the University of Wisconsin-Madison, he worked over 20 years on TV and radio in Milwaukee, Madison, Omaha, Nebraska and Kansas City, Missouri.

Craig spends most of his time trying to keep up with his bride and their three teenage daughters. Any time left over is spent with his other beloveds, the Packers, Brewers and Badgers.