The "bluing" on your pans comes from excessive heat. Stainless cookware requires lower heat than other materials. So, for starters, lower the heat. And pre-heat the pan as well.
Meanwhile, Bar Keeper's Friend will polish out those blue spots.
Bluing as a metal treatment, however, is not the same thing. To achieve it, the metal is bathed in specific caustic salts to create a controlled rusting effect that protects the metal on a molecular level. It's most often used, as others have stated, for gun barrels. Browning is a similar process, that has been superceeded by bluing---which, nowadays, has been in turn superceded by other processes.
They have taken the oath of the brother in blood, in leavened bread and salt. Rudyard Kipling