To change the color scheme of the trees:

1. Rename the current "Images" folder to "Images (DEFAULT)" or something

2. Choose one of the two other folders, "Images (MULTICOLOR)" or "Images (ORANGE)"

The ORANGE folder makes all of your trees orange. MULTICOLOR is similar to the default except with more vibrant and varied colors, which may make things look a bit too cartoony.

3. Rename the folder whose textures you would like to use to "Images"

The game will now read the "Images" folder you have renamed as the folder to use the textures in. You should see the trees colored differently in game.