I think that's a rubbed finish, where they applied bronze spray and let it harden, then sprayed with black and partially rubbed it off with a rag.
Or (more likely) the other way round (because bronze paint is more expensive so they'd only use a trace).
To simulate wear.
Your own paint will NOT match the factory finish.
Paint the pipes to match the wall.
Edit:
Looking again, I think the metal was painted black, then lightly rubbed with a rag holding traces of bronze paint. This is much more economical in materials, but not very convincing.