It's time to check your assumptions. Exactly what is the cable intended for? Is it UL/CSA listed? Or, was it "imported" from the mines, where MHSA rules apply? Was it scavenged from some other non-electrical application (such as aerospace, rail, etc.)?
Otherwise, regardless of the source, wires that can be seen need to be marked in accordance with the NEC. The code discussed only four colors (white, green, orange, and grey), and these guys violated three of them.
