On Airbus aircraft, fibre optic cable can be identified by its jacket colour, which is

Thanks for flagging this - you are right.

Fibre optic cable on Airbus aircraft has a purple (violet) outer jacket. The Airbus-qualified fibre cable (ABS0963 / EN 4641-100) is purple, which matches what you saw on the A320neo.

This question was originally keyed purple. Earlier this year it was changed to orange during a review, on the basis that orange is the standard fibre colour. That is true for ground telecom cabling (TIA-598 uses orange for multimode and yellow for single-mode fibre), but it is not how fibre is identified in Airbus aircraft wiring, so that change was a mistake.

I have moved the correct answer back to purple and rewritten the explanation. The question now also says which aircraft it means, so it no longer implies one colour for every manufacturer:

"On Airbus aircraft, fibre optic cable can be identified by its jacket colour, which is"

Hands-on checks like yours are the best way we have of catching this kind of thing, so please keep reporting anything that does not match what you see on the aircraft.