Only one way it can be done, make a texture or a spot on an existing texture, that color blue with a fade from one end to a lighter blue on the other, then map each tube to it with the darker part of the fade on the bottom, so it looks rounded.
There is no other way to make that. That's not metallic blue anyway, thats a candy blue. That only looks right in game with certain colors, burgundy, greens, and some teal blue/ green colors, which if you do get the right color you want, it will look perfect on some tracks, and others it will be a pastey mint green color on others.
I made my custom 1988 Chevy shortbox a candy orange, so it can be done, just gotta mess with it till you get the right color and lots of fancy shading and shadows.
Rep Fan's Garage