Here are a couple of plants that give me a taste of fall colors year round in Mexico.
The leaves start out a solid green and gradually develop yellow spots which eventually turn red. I am not sure if this is supposed to be a tree or a shrub but it's more like a tree. Currently this plant is around 10 feet tall. Now take a closer look at the leaves to see all the different colors:
This next plant is similar to the previous with the leaves coming in green and the colors developing but with a couple of differences. It is more like a shrub being between 3 and 4 feet tall. In addition, instead of the leaves being flat they are twisted or wavy.
In a closer look you can see the difference in the leaves but still pick up on those great colors.
My garden area isn't that large, but I can imagine having a really large area with these plants scattered among palms and fruit trees.