What would be an appropriate recolouring?
I think either red or gold works. I mean, the First Order sometimes uses the color red, like the red banner in Hux’s speech or even the new Sith Troopers in IX. And as for gold, as the other user pointed out, there IS a golden Stormtrooper in Resistance.
If you think it’s that easy, maybe you should give it a shot.
I don’t have After Effects, but I’ll put a photoshopped image of Phasma here. However, I currently have school, so I’m too busy to do this. I’ll do it over the weekend, if I have time.