Greetings Gary:
Okay, I'll give your question a shot :-) However, please note that I am definitely not a tree/plant physiologist.
Source: Pallardy, S.G. 2008. Physiology of Woody Plants, 3rd Edition.
Source: http://scifun.chem.wisc.edu/CHEMWEEK/fallcolr/fallcolr.html
Energy capture and CO2 fixation occur in the chloroplasts of higher order plants – chlorophylls (chlorophyll-a and chlorophyll-b) are the most important pigments found in chloroplasts. Additional “accessory” pigments present in plants include carotenes such as B-carotene and xanthophylls.
The absorption spectra of the chlorophylls indicate two peaks of absorption in the visible region, one in the blue and one in red wavelengths, 450-495 and 620-750 nm, respectively. The relative absence of absorption in the green region clearly illustrates why these pigments give plants and much of the world a greenish color (i.e., green wavelengths are reflected and not absorbed by the chlorophylls). Leaves of a few varieties of trees such as copper beech and Crimson King Norway and Japanese maples are red or purple because of the presence of anthocyanin pigments that occur in the cell sap of the vacuole rather than in the chloroplasts. Anthocyanin pigment, with their intense absorption of solar radiation in the photosynthetically active blue wavelengths, protects the photosynthetic apparatus from oxidative damage.
Anthocyanin pigments, responsible for the pink, red, and purple colors are related to the carbohydrates and carbohydrate accumulation favors their formation. Anthocyanins and glycosides formed by reactions between various sugars and complex cyclic compounds called anthocyanidins – they are water soluble and usually occur in the cell sap of the vacuole. Anthocyanins usually are red in acid solution and may become purplish to blue as the pH is increased. The amount of anthocyanin pigments depends primarily on the possession of certain hereditary potentialities for their production, but environmental factors also have an influence. As chlorophyll synthesis stops, the chlorophyll already present begins to decompose chemically and the newly formed anthocyanins are unmasked. In those species that do not form anthocyanin pigments, the autumn breakdown of chlorophyll unmasks the relatively more stable yellow carotene and xanthophylls pigments; or there may be an admixture of red anthocyanin pigment with yellow carotene to give a bright orange color, as in some species of maple. In other species both chlorophyll and carotenoids disintegrate simultaneously and new carotenoids are synthesized. Thus, by disintegration of green pigments and the unmasking of yellow ones, the formation of red pigments, or all three, the leaves may assume various shades of yellow, orange, crimson, purple, or red.
Carotenes (cell membranes; chloroplasts): absorb blue-green and blue wavelengths; thus the light reflected appears yellow to our eyes.
Anthocyanins (not attached to cell membranes; cell sap): absorb blue, blue-green, and green wavelengths; thus the light reflected appears reddish to our eyes.
Chlorophylls (cell membranes; chloroplasts): absorb red and blue wavelengths; thus the light reflected appears green to our eyes.
Carotene & Chlorophyll: absorb red, blue-green, and blue wavelengths; thus the light reflected appears green to our eyes.
So, a very general answer to your question may be the general theme associated with the major pigments found within native plant leaves: blue wavelength light is generally absorbed and not reflected. Hence, there are few true blue-colored summer or autumn leaves. Of course, there are exceptions.
I’m sure I will receive constructive feedback if I unintentionally misrepresented any information contained in my explanation :-)
Sources: Pallardy 2008 and scifun.chem.wisc.edu