They used to make a Mil Spec 9mm in matte blue or Parkerizing, maybe you could find one on the secondary market.
Otherwise, if you want a dark SA 9mm, you will have to throw money at the problem. Cerakote, Melonite, Ionbond, chromium sulfide, and maybe other processes will blacken stainless.
I just put up with it. For example, I do not much like the reverse two-tone style, but have two because one was at too good a price to turn down for cosmetics and the other was not available any other way at all.