S&W did trademark the case coloring on their hammers and triggers, but it wasn't matter of pride. S&W was being hurt by the influx of Spanish revolvers that copied S&W. Not only did the Spanish junk take sales from S&W, but when the Spanish guns broke, the owners expected S&W to fix them!
One of S&W's responses was to trademark the case coloring. If the Spanish didn't copy it, the guns would look less like S&W's; if they did, customs would impound the guns for trademark infringement. (Patents expire; trade marks do not as long as they are used and defended.)
Jim