Some years the maple colors are spectacular. Although the trigger for
change is the fading autumnal light, the color and intensity has to do with
rainfall over the summer, the concentration of sugars in the leaves, the
temperature drop, and the die-off rate of the plastids containing the
chlorophyll, xanthrophyll and anthocyanin. It's the anthocyanin that makes
them red and they only look like this if everything is just right.
The first pic is from 2001. Last year (2015) these same trees were a
shimmering golden yellow as you see in the second pick.

Every March when the sap runs my neighbor Jay taps these trees and
gives me a jug or two of some of the best maple syrup on the planet.
 
Here's a love poem from a few years back:

10/10/96
 
my one desire
on this golden perfect
October day

 
is to be deep inside
the bright maples

 
to dance
in tumbling streams of color
until i

 
vanish

 
--