I use red for everything except alum, I use green on aluminum. 3/32" here as well with a #7 cup (most of the time)
I agree with turbotank on the stainless. I've welded quality stainless and it welds nice, but seems like every time I weld a set of "stainless" headers, it seems to get "ugly" "slaggy" welds (like the ones you posted). I say those in quotes, because there not really ugly or slaggy, just not what a TIG should be IMO.