Air Line color

yes,
black - wet air (charging)
green - tank #1 (primary)
orange - tank#2 (secondary)
red - tank #3 (park brake and trailer supply)
yellow - park control ore service brake (really there are front, rear, trailer brake control lines, color may differ)

Blue ore yellow spiral line- trailer control line
red spiral line - trailer supply line
(glad hands may be marked with same colors)

trailer air lines are usually black, but if marked - red - supply, yellow - trailer service brake..

 

European truck maker usually fit black tubes, sometimes number marked.

But every tank has label and every control port has small sticker too.

But some trucks have a bit different air line routine, but aniway air line system meets DOT and ECE requirements

 

brown.... may be it is orange, but old... color may change

 

Can you use black instead of red rubber covered airlines

 

I don't believe there is any rule saying you can't use whatever colour airline you want.

 

Funny thing is most of the time all the color coded lines get coated with either black or whatever color the frame and or chassis gets painted. Always looks like crap even when new. If I am dealing with a truck that has all the cheap plastic lines I do them all black. Most prefer a clean look instead of a cluster of bundled multicolored lines. They are more hidden and easier to do touchups on them and looks better in the long run as they age.

 

Funny thing is most of the time all the color coded lines get coated with either black or whatever color the frame and or chassis gets painted. Always looks like crap even when new. If I am dealing with a truck that has all the cheap plastic lines I do them all black. Most prefer a clean look instead of a cluster of bundled multicolored lines. They are more hidden and easier to do touchups on them and looks better in the long run as they age.