That is how I did my 4 color mini-trees. I have 16 of them and I created models for each color for each tree. It is time consuming but once you have the 4 color models for a tree, place then almost on top of each other and be done with it. The layout process does take time but once you have it completed you can leave it alone. Also, suggest you set up model groups for each tree and assign the 4 colors in my case to that model group.