The background of the new combadge is not black; it looks more like a satin-finish (semi-matt) dark bronze sort of colour, as against the mirror-polish silver/chrome finish on the arrowhead/delta symbol.
This is likely why the background still looks gold in one early pic of the pins given away after the Premier. I guess it’s all down to how the metal finish catches the light.
Looking at some of the better close-up stills of Adm. Clancy, it looks like the flag officer rank bars have been cast and finished in the same way: the pips and the border are polished silver and the background of the bar looks to be the same dark bronze as the background of the combadge. This is quite a nice design feature and, with the new standard silver rank pips, makes for a cohesive overall system between the rank insignia and the combadge.