I had to turn the transparency down to show the grey more, but it works too. I still prefer blue. In the blue design the disabled buttons would turn grey anyway.
Yeah, the centering with non-regular shapes is irritating (another argument against a pure shard design). These are just sketches anyway, once a new GUI is actually put in the game things like that will have a lot more attention.
Oops, my fault. I accidentally made CO2 purple based on one of @braguy.j's icons.
That's still the existing cursor, I forgot to add a new one.
Definitely, and you can see that with the bigger design.
No...? Well, in real life it is, but not in-game.
I'm not sure that screams DEATH quite so clearly as a skull and crossbones but it could be replaced.