Exporting Blender model as .ply with Vertex Color embedded with the model


I have this hefty in size 3D model of the bulldozer (lego) blender model 3D and I need to export the geometric mesh including colors / per vertex. I need in .ply format as it’s one of the formats supporting vertex coloring as far as I know and it’s easy to include the model in Python for Neural Mesh Reconstruction and Validation later on. I’ve tried to export as .ply by marking the checkbox Geometry -> Vertex Colors, but the resulting file has all colors set white (255, 255, 255, 255). Can someone tell my what I am doing wrong and how to do it properly.

Using blender 2.81. The URL for the model: https://drive.google.com/drive/folders/1z04KznmTyfayrYBfhNo8Q7su4FWMulfs?usp=sharing

Thank you in advance.