ID has to be 3.4mm or about .130" . I could care less about the color. Although, I was thinking of making up a few harnesses to see if there was a market for something a little cheaper than some of the online shops sell them for. I wonder if people would care that the tubing was not black "official Gibson" tubing.
BTY it's also called spaghetti tubing.
If worse comes to worse I'll look for thick wall shrink wrap. Should look the same