Change the date of your session in Environment setting to fall (depending on the region / world origin is will be Northern or Southern hemisphere seasons). I belive most are seasonl (but happy to be proven wrong)
Tony, thanks for taking the time to reply. Your suggestion works for the trees that are already on the route, clam1952 trees, but not Pofig's trees. I'm hoping that he actually made fall colored trees and someone can give me the proper designation.
John, yes I knew that Pofig's trees were not seasonal. I'm still hoping that he made some with fall colors. I think I have most if not all of his trees but I dread the thought of having to search through them all especially if he didn't make any. Hoping someone here on the forum knows the answer. Thanks.