When I used the bolt armor trim on a full set of Gold Armor in Creative Mode, the next one I got appeared to have it on in the inventory gui. I uploaded a recording to Google Drive (it was too big to fit here) and the link is here:

https://drive.google.com/file/d/1Z-hpB6m1elsGkoHhz5YQTy1d-FgjbxRm/view?usp=sharing

Note: I did NOT put any trim on the gold armor in the hotbar (except for the golden helmet at the end of the video)