Fall colors last 15 or 20 minutes in pots that you don't pay much attention to in that season. Not worth the effort in most years. In 20 years of bonsai I only have a couple pictures of autumn colors worth the effort in spite of having two of the best, Japanese Maple and Korean Hornbeam. Good autumn color depends upon having good autumn conditions which are, killing the foliage suddenly while it is in good condition. This happens with an early frost in September which doesn't happen that often in my area. A hundred miles north is a different story. So, if you get good color in your neighborhood, go for color. If the local trees just peter out in a long autumn without frost before November-ish weather sets in, so will your tree and you'll get no reward for having a tree that is colorful in areas that's have "color tours" in autumn.