The colour where the glaze ends around the bottom is reddish brown. Unfortunately there is not much I can add since you are pretty much on the right track already. I can only confirm that the Jar is nice but as you suspected, not antique. The decoration is a war scene, possibly based on a theater play or book illustration - and unfortunately beyond me to identify. This information is given as an example of private conversation only and is not intended to be used as a promotion of any individual piece.
All opinions is the authors and is given as such with all hazards of judging anything from a photo.