The impedance is different but this is something you may neglect as we are not talking about high-end equipment here
Technically there are two wires in both cables: signal and ground.
Black and white usually happens for two reasons:
- Setting output to RGB but it is only S-VHS (or the other way around, can't remember which one)
- Playing an NTSC disk and set PAL or Auto in the video setting instead of NTSC (doubt this will be your case)
I suspect you need to adjust the video settings in the setup to output the proper video signal