Is change an action verb

Yes, change is an action verb.

EXAMPLE: The leaves change to a pretty red and orange in the fall.

Change is an action Word being the leaves turned, or changed, red and orange. They actually did something. It also works with these sentences:

Allison changed out of her wet bathing suit and into her dry clothes.

OR

Ever since Megan invited Olivia to her table, she's changed, and doesn't seem to like us anymore.