Here's a metallurgist's comment !
Damascus [ more properly called 'pattern welded' ]is a mixture of two or more steels welded together . Many interesting patterns can be created such as a logo on a blade. While true stainless pattern welded blades are made they are difficult to do and rare. There are 'Damascus' stainless steel blades but they are made from alternating types of stainless powders compacted together.
I have a rolling block repro rifle case hardened by Turnbull , it is gorgeous !!! Color case hardening is a very difficult job requiring much experience and is used as decoration rather than hardening.