Paint the chest armour, ankle/shin pads and shoulder pads metallic instead of synthetic. The metal (specifically gold) for carapace armour seems to be what an old guide I found suggested.
I also suggest painting the hands as gloved instead of bare, maybe freehand an armour plate on the back of the hand too.
If you have lots of spare helmets with lenses and rebreathers you could also perhaps use them to add extra visual distinction and a bit of extra protection too!