def METHOD_NAME(self, b_obj):
    """Create vertex colors"""
    bpy.ops.object.editmode_toggle()
    bpy.ops.mesh.quads_convert_to_tris()
    bpy.ops.object.editmode_toggle()
    # add base vertex color layer
    bpy.ops.mesh.vertex_color_add()
    b_obj.data.vertex_colors[0].name = VERTEX_COLOR_LAYER
    # iterate over each face, then set the vert color through lookup
    # TODO [geometry][vertex] use vertex coordinate to map vertex color
    #      (we should not rely on vertex ordering)
    for face_index, face in enumerate(self.b_faces):  # nif_faces: 0-11
        for vert_index, n_vert in enumerate(face):  # nif_verts: 0-7
            b_meshcolor = b_obj.data.vertex_colors[VERTEX_COLOR_LAYER].data[face_index]
            b_color = b_meshcolor.color
            b_color.r = self.vertcol[n_vert][0]
            b_color.g = self.vertcol[n_vert][1]
            b_color.b = self.vertcol[n_vert][2]