You know all the color hookup wire that's very thin inside walkmans. I've never been able to work out what the gauge is despite measuring it.
Most are around 30 AWG, but some walkmans use more than 1 gauage (like thicker for power lines). But there's another factor: how thick is the insulation. As some wires may be overall thicker, but have the same gauge inside as thinner ones.
I looked through the service manual for some Aiwas, and they don't even list wires in the parts list, or specify thickness. But color is specified.