Greetings. Yes, Smith & Wesson used to produce a beautiful carbona blue which was known for its luster and richness. The factory discontinued that in the 1980s because the Carbona bluing process was harmful to the environment and also was expensive. They have since used an acid blue which lacks the beauty of the older blue, but is just as resistant to holster wear and corrosion (which isn't saying a lot).
If you have an older Smith, you might want to keep it as you'll never see such bluing again. Some independent finishers can come close (fer a hefty price), but most use what's called a nitre blue that is close, but no cigar. Very few if any use same process Smith used, so if you have a piece blued, ask about the process.
Still, you said your 29 was beautiful, so I wouldn't worry about it. But when you see the bluing Smith and Colt used to use, you'll be impressed.