Thanks for replying, David. By chart do you mean white card or macbeth color checker? I am interested in tips on what settings might need adjustment (hue, saturation, etc, cine d/v/natural) to bring GH4 and GX8 closer to the same look in camera. Thanks.
Hard to say after the fact, but I would start by finding white with each camera.
As far as a chart goes, get what you can afford. Something which shows your color info on your vector scope is nice, along with your white and black points.