It’s that time of the year. The leaves are starting to change colors. This week the National Weather Service in Atlanta shared the satellite image above showing fall foliage changes in the Appalachian ...

Photograph by Christian Ziegler, Nat Geo image Collection In nature, the ability to change color can be key to survival. Vision is a very important sense in much of the animal kingdom, and many ...

Dr. Mark Lindsay was 5 years old when he first learned that tree trunks were brown. "Up until that point, I believed leaves and trunks were all green. Just lighter and darker shades," Mark said. Mark ...