Case coloring on most modern firearms is nothing more than a cosmetic
coating. The Westerner is manufactured with a true case-color hardening.
You see, this process of case hardening has been around for centuries.
It has been used to make metals harder, in order to enhance it's
performance. The coloring is a by-product of that hardening process.
When done properly, the residual coloring by-product of this process
can be manipulated to provide a greater esthetic appearance. Bur remember,
the coloring is just the by-product. The real benefit is in the
hardening which provides greater strength, and longer life to the
material itself.
The normal Rockwell hardness for a standard carbon or stainless steel
slide is about 38c. Once case hardening process has been done on the
same piece of metal, it will Rockwell in the high 50's to low 60's range
on the same c scale (the actual hardness will vary from part to part, as
the process is controllable. Hardness will also vary depending on the
type of metal that is being treated as well).