In which format does Unity read vertex colors from .obj files?

I couldn’t find a definition for vertex colors in .obj files.
Some exporters write additional lines per vertex, starting with ‘vc’. Wikipedia suggests to write 3 additional values at the end of each ‘v’ line.
I tried both but without success. I am sure I used a shader that would show vertex colors (it did on another mesh).

My question: Which format for vertex colors in .obj files actually gets read by Unity?

I used MeshLab to export in .dae format (for some reason .obj vertex color couldn’t show up in Unity for me)

Then you have to choose the mesh you imported into Unity, change the shader to “Vertex Colored” for its material.