I don't do the salt. I myself use hot tap water. Bring to boil. Boil for 14-15 minutes. Put into bowl with cold water running over them for a few minutes, then peel. My yolks aren't discolored at all.
I just hard boiled 36 eggs. Brought the water to boil, ladle eggs (18 at a time) into the boiling water. Boiled for 14 minutes, ladled them out and put in a bowl and ran cold water over them, then put the next 18 eggs in the water and boiled for 14 minutes. While they are cooling in cold water...