What's this treatment called? Is it different on the aluminum frame and the steel slide? Going to do some front cocking serrations, maybe a port job. Can this coating be re-done at home?

good morn,

I thought some one with more experiance would chime in by now, they didn't so here goes.
Alumablack or some other similar product works well on the aluminum.
Cold blue works not so well but with lots of cleaning, solvents and then hot soapy water, you could do a OK job on slide serations. I have used it for not so important jobs with some success.
Burch Casey seems as good as any.

ace

Slide looks more black then blue. once the new serrations are done, like to redo the whole slide