How can I get the color in the middle of a face using Python? Say I have a mesh and I have colored the vertices using vertex paint, how can I then get the average of the colors or rather the color in the middle of the face or the color under the normal (shown below) using blender python?
In the middle of a face is an average color of all the vertices. For triangle this means:

Col_RGB = ((R1+R2+R3)/3, (G1+G2+G3)/3, (B1+B2+B3)/3)

Where each vert has color in form of (Rn, Gn, Bn) for n in (1..3).