This is mostly owners preference but thought I would ask anyway. I'm finishing up some smaller pieces that I'm prepping for paint but would like to hear you comments on which color is correct for them. For now I'm working on the brass radiator pipes, hydrovac vacuum lines, engine vacuum lines and throttle linkage. I need to know what is the correct color to pain each.

The color choices are OD green, black or engine gray. I'm thinking OD green for all hydrovac lines. for the engine vacuum lines and throttle linkage I was thinking black and not sue about the radiator lines. Let me know what you think.
Thanks,
Steve A.