Iris Cohen wrote:

I discovered that not only does the same tree have different colors different
years, as Archie & others pointed out, but climate & location play a part. Soil
pH was also mentioned..

This is also true in Texas for oaks. We're not known for our fall
color down here. Most of our oaks just turn paper-bag color and drop
their leaves, but one year in about 15, we have just the right
combination of warm days, cool nights, and perfect moisture and we see
russet and peach and gold. It's enough to make a botanist play hooky
to go out and enjoy. It does not look as if this is going to be such
a year...

M. Reed
College Station, TX