The green in the trees here in Seattle are turning into reds, oranges and yellows, as they are across the United States.
So why are leaves green to begin with? asks Wikipedia in its article on chlorophyll. Wikipedia : ‘It still is unclear exactly why plants have mostly evolved to be green. Green plants reflect mostly green and near-green light to viewers rather than absorbing it. Other parts of the system of photosynthesis still allow green plants to use the green light spectrum (for example, through a light-trapping leaf structure, carotenoids, and so on). Green plants do not use a large part of the visible spectrum as efficiently as possible. A black plant can absorb more radiation. For more, check out Wikipedia : Chlorophyll