Hello Michael,

I'm not familar with obj-files. A while ago I read the posted document without interest in coloring, only by the way I saw something about vertex Colors.
It seems, that it is used in connection with textures. Nevertheless I painted a face of a cube in Meshlab. I can't decide if there is a difference in the structure of both files.
Test.obj -> Export from MoI
Test2.obj -> Import Meshlab - painting -Export

Have a nice day
Karsten
p.s.: Forgot the Material