I have attached a screenshot, but I think things are working as well as they can be now.
I was getting confused because things were happening either very quickly, very slowly or apparently not at all, and the colour mapping between PM and XMP, didn't match the colour mapping between XMP and C1/FRV.
I have now chosen the Lightroom option in PM, for colour mapping which only gives me 5 colours, but at least they map to the same five colours in C1 and FRV. Before this C1 and FRV were matching colours correctly but PM wasn't.
C1 seems to randomly sync automatically and immediately, while at other times needs a manual reload of the metadata before any changes occur.
FRV seems to also read and write to XMP rather randomly and there is no way of forcing a read/write. So sometimes it would update immediately and other times it seemed to not update at all.
I focussed in on PM as it "seemed" to the one program that wasn't showing the changes I expected, but I think it was the combination of things going on that I didn't understand.
I now don't think the issue is PM, its me trying to sort out how these programs work together.
Sorry for wasting your time.