This time of year the trees seem to come alive bursting with colors of orange, reds and copper, but why does this happen? Our friends from EarthSky share how this process works each year. Throughout the spring and summer, the deep green color of chlorophyll, which helps plants absorb life-giving sunlight, hides any other colors present in the leaves of trees. The vivid yellows and oranges of fall leaves are there, but hidden. In the fall, trees break down the green pigments and nutrients stored in their leaves.