The basic options are:
1. Restore case hardening colors, which requires repeat of the hardening process.
2. Try to replicate case hardened colors with chemicals, which generally misses the mark in my opinion. Several new guns are sold this way.
3. Strip +/- color with bluing solution.
4. Clean it up and call it patina...
If you decide to restore the colors, there are several professionals who specialize in this. It's probably not worth the time and equipment and learning curve for you to do it yourself especially if for just one gun. There are YouTube videos that can give you an idea of what you would be getting into.
Last edited by Woodreaux; 05/08/19 09:32 AM.