^^^The present (and long-standing) color is "International Orange", supposedly the most visible in fog:
http://goldengatebridge.org/research...tedIntnlOrange
I don't know if the steel parts were pre-primed.
I too have walked across--I was at midpsan when this picture was taken at the bridge's 50th anniversary along with 300,000 of my closest friends. Note the deformation (sagging) that number of people caused at mid-span:
If I'd known that was happening, I would have got off the thing as quickly as I could (likely not very quickly).