Ive got a gun metal black vamo v4, and I have an aerotank mega, the tank looks great on my vamo, however, I would love to have the color of the tank match the vamo, I was looking online and i found... perma blue, its a product used to make gun parts that famous gun metal black, on the bottle of perma blue it has a ton of safety warnings, do you think I could safely apply the permablue to the outside and only outside of my aerotank? do you think it would still be safe to vape if I didnt get any on the inside of the tank?