The library windows opened
all the books flew out in pairs
The school kids sat in wonder
as the librarian became a bear

She grunted and she snorted 
“Get those books back in” she roared
But nothing, nothing could stop them
as into the sky they soared

When days grow short and nights grow long,
trees start to grow a corky layer
that cuts through every leaf-base stem.
Like falling books, unloved, condemned.

No chlorophyll to ink leaf’s page,
green’s superficial stories fade
revealing deeper colour’s signs,
like reading in-between the lines.

Xanthophylls are coded yellow.
Anthocyanins, red-purple.
Carotinoids have orange gowns
while tannins turn their pages brown.

Here’s a lovely link showing all those leafy autumn colours:

https://www.livescience.com/16508-fall-leaves-rainbow-gallery.html