Autumn is probably best known for its gorgeous and varied colors. Deciduous trees in more temperate climates respond to autumn’s cooler temperatures and shorter daylight hours by changing their leaf colors and dropping their leaves to the ground. A rainbow of purples, reds, yellows, oranges and browns take over where shades of green once dominated. What causes this transformation? Like the people and animals around them, the trees are preparing themselves for winter. Cold weather early in autumn and/or dry conditions over the summer months make for less than spectacular shows of color and early leaf drop. So, what causes the picturesque colors we love?