My last reply deals with per-vertex colors. I just want to clarify something
MFnMesh.SetVertexColors() and MFnMesh.SetFaceVertexColors() do pretty different things. From reading your posts it seems that what you’re looking for is MFnMesh.SetVertexColors().
I rarely ever have to do this, but if you need to deal specifically with face vertices, then it can get a little more complicated. It’s not the same thing as setting per-vertex colors, since you can actually assign a unique color for each face connected to a particular vertex.
