Does the gas mask look well with my armor
depends on the look your going for. The first one is a classic armored warrior look. The second one looks a little sith warrior-ish.
If you can dye the glass, maybe something a bit more golden to match the tunic/rose?
Nothing. The medieval/futuristic mix is too jarring IMO. It’s like playing a medieval RPG with an F-22 final boss. If I had to wear the gasmask, I’d use the aetherblade armor to go with it. Maybe the CoE one, but that’s it.