John, I'm afraid for me your plate leaves more questions than answers. From the enlarged pictures I cannot decide for sure if it is Wucai or not. It would have to be, if it were anytime Ming or early Qing dynasty. The green decoration in the central medaillon seems to be painted rather in a late Qing fashion.
Then, I have doubts about the underside flower decoration. I have never seen this on very old porcelain plates. The red flowers on the top side look very much as if it could be 17th century, as does the footrim, but I am not so sure about some of the colors. Generally, it gives somewhat the impression of the red-green export wares of the period, but it is in much too good a condition for that, in my opinion.
My experience is insufficient to tell what it is fromt he pictures alone, I'm afraid. For me it would be necessary to feel the surface and inspect the colors and footrim with a magnifier. I would need a hands-on inspection with this one to decide anything else, as I think with this plate too that something could have been added later. The first impression looking at the decoration alone was it is either Kangxi or Guangxu, but the underside ...