The White RoyalGuard+++ is the one on the left, because it has lighter colors. I used Paint to double-check: the color of the shield inside the star is rbg(118, 118, 118) for the left unit and rgb(88, 89, 89) for the right unit.

I dunno how CEO draws the pieces it uses, but if it's at all dynamic maybe you could have the border of the piece gently glow gray (at approx rgb(140, 140, 140) for a voided piece?