To add to the confusion, multi-mode (shortwave, 850nm) fibre optic cable is orange whereas single mode (longwave, 1300nm) is yellow. But I have noticed the coax S/PDIF equipment jacks are usually painted orange.
And in my experience with my digital audio equipment, basically any RCA cable will do the job to carry the coax AC3 signal. In fact at one time I had my old, worn 20-foot Atari 2600 RF cable (that goes to the TV/GAME switch) on there and it was just fine. Think about it, it's simply a low current serial electrical connection. I personally think the Monster brand cables are a ripoff. A lower gauge core, and all that extra shielding and outer rubber insulation, is not going to make one 'bit' of difference in a digital connection. Even for analog composite video or stereo RCA connections it's not really necessary.