Instructions:
Divide the dough into five sections. Keep one section aside; this will be the tan section. Stir some yellow food coloring into the second section and work it in until it looks distinctly yellow; compare it to the tan and make sure that you can see the difference easily. Now take a third section and work red into it until it is red (not pink, it'll probably turn pink first!), and finally take the fourth and work orange food coloring or a mixture of red and yellow into it until it is distinctly orange. Finally, when all the colors are done but one, mix the cocoa into the last section for a brown section.
Take half of each of the five doughs and smush them together lightly. Then roll them out on a heavily floured sheet as one mass. You might choose to mix the colors a bit so that it is more multicolored, but do not actually knead the dough before rolling or you will get a brown mess and you want them to look like changing fall leaves. When you have the combination you want, cut out multiple leaf shapes with some different-shaped leaf cookie cutters. Place them 2 inches apart on lightly greased cookie sheets. Re-roll the scraps, adding bits of the "fresh" leftover dough to supplement. Keep going until you have used all the dough. Bake the cookies at 350º F for 10 to 15 minutes--the edges should be lightly browned. Cool them completely on wire racks before going to the next step.
Get a sealable plastic bag and put the chocolate chips in it, then microwave until melted. Make sure to knead the bag in between shots with the microwave to make sure all the chips get melted. Cut off a very tiny corner of the bag and use it to pipe the chocolate onto the leaves in little vein patterns. (This last bit is not ABSOLUTELY necessary, but it really enhances the effect a lot, so I recommend doing it.) These are served well with milk or spiced cider.