Here is an activity pack from the publisher, Random House. Print out page 2 and have students color and cut leaves, then create their own pictures on another piece of paper using the leaf cutouts.
For students who are more concrete in their thinking, 3dinosaurs.com has an amazing array of printable activities, including tracing, what-doesn't-belong, and sorting.
Dance to this video:
For students who are more sedate, watch this and ask for answers:
Song about leaf colors: