I would like to know if there is any color code specified for CAN Bus communication wiring, maybe in ISO-11898-1? (I have no free access to the file)
I looked for any official documents without any luck.
When I asked to my colleagues about it, they all agree on the colors (Yellow and Green) but they do not agree if it is:
or instead:
The ISO 11898 standards do not mention practical things such as cables and connectors.
The second-most authoritative source has therefore become the CANopen standards, where DS303-1 specifies things such as standard connectors, pin-outs, cable lengths, baud rates etc. Unfortunately, this document does not mention color-coding either.
Yellow and green seem to be commonly used, though I have seen yellow mean either CAN High or Low. However, just because these colors are commonly used, it does not make them more correct.
I'm guessing that the yellow and green comes from the universally standardized color-coding (same as we use on through-hole resistors). That is: 1=brown, ... 4=yellow, 5=green. For the "mini style" and "micro style" (round M12-like) connectors standardized by DS303-1, CAN High happens to be on pin 4 and CAN Low on pin 5. From DS303-1 7.2:
This enumeration is however not at all consistent with other common, standardized connectors such as d-sub, RJ45 and terminal socket.
CAN does not have a formalized physical-layer specification for conductor colors, or things like connector type or pin-out. There are common practices (like using a 9-pin D-sub connector) but no official standard.
Vehicles these days also tend to have multiple CAN buses, so colors will, of course, vary to keep the different buses straight. I have seen some buses adopt a solid color for CAN-L and a different color striped with the corresponding CAN-L color for CAN-H, to give a visual impression of belonging together.
Overall, as long as you keep track of your conductor colors and pinouts, you can use any color scheme that suits your preference without violating any standards.
I found a link for J1939 cables (not sure if this is generic): see link
Excerpt (see last two lines):
CBL-CAN-01: CAN Cable for DB9 Male Connector
This is a 4-wire color coded cable. One end is DB9 female connector,
it is designed to mate with Au J1939 products at bus side, such as:
J1939 Message Center System, J1939 Data Center System,
J1939 Simulators, etc.
The other side of the cable are 4 pig-tail wires.
Red wire: Power supply, +12V
Black wire: Ground
White (or Yellow) wire: CAN High
Green wire: CAN Low
From 'John Deere' : Link
Red is Power - 12 V
Black is Ground - 0 V
Yellow is CAN High - 2.5 V
Green is CAN Low - 2.5 V
In every implementation I've seen, if you can imagine that one color represents "Sky" and the other represents "Earth", those happen to be Hi and Lo, respectively.
Et cetera. These mnemonics seem to fit so well I have to imagine they're intentional.
CAN_H = yellow, CAN_L = green per SAE J1939-11.
This would only apply to J1939-compliant CAN installations.
The CAN Bus wire is a 4 conductor.
Two wires are for power regulation: CAN Power (Red), CAN Ground (Black).
The other two wires are CAN High (Yellow), and CAN Low (Green). A useful mnemonic to remember is sun is yellow and high while grass is green and low.
Of course variations exist, in which case referring to the manufacturer's guidelines is essential.
