More ash trees: https://3dsky.org/collection/shared/5251731 

Deciduous tree Ash 16.4 meters high.

A trunk with branches and foliage are separate objects. If necessary you can remove the leaves partially (randomly select subobjects in the ribbon panel) or completely (for a bare tree as in the preview) or draw VertexColorMap.
In the scene there are four cubes with different materials for the ash tree according to the seasons:
– summer;
– autumn;
– summer autumn;
– late autumn.
For the last two draw vertex maps on channels 2 and 3 respectively. To do this apply the VertexPaint modifier to the foliage fill the model with black and a white brush about 2000 mm in size draw areas where there will be green (for the summer-autumn option) or red (for the late autumn option) leaves. Added screenshots to the archive. Then through CoronaLayeredMtl mix the desired types of foliage using the vertex map as a mask.
Thanks to CoronaMultiMap CoronaColorCorrect and vertex maps you can customize foliage shades to your liking.

Done in GrowFX2.

Polys (Editable Mesh) – 3 165 531