in the collectors view, ANY gun you re blue will LOOSE value, period, to a shooter the value MIGHT go up
so will come down to WHO the next buyer is, a collector will NOT pay more for a gun NOT original, over one that is, its the game!

a shooter or a guy that doesn;t know any better, well then its a different game and your counting on inexperience here and not knowledge of the buyer
and in that case, old saying," a sucker is born ever second" LOL

NOW< the BEST option to KEEP value would be to have COLT re blue the gun(far from cheap option here)
BUT should gun in a 100 yrs become a desired gun, the paper trail of work being done by COLT will add value to it over JUST any smith doing the blueing, as Colt NOW< any ways, offers letter heads on collectible guns with history trails best they can, and again collectors PAY more to have this stuff on paper, NOT bill of receipt from "X" gun smith either
as many times in life, WHO does the work can add or decrease value of things, to a COLLECTOR for sure, and even to the average Joe!
Branding is every where today!

if you ONLY plan to shoot the gun, why not do a better coating on the gun, like a Black Ice if you want blue look, or cerakote it, more durable than blue, and might even be cheaper than a good blueing job?

won't add any value to it on you, and to a collector, it will DE value it

but will be a great gun to carry and use from here out!