nearly any rca cable will work for a digital coaxial connection i believe. there is potentially a problem with using red/white/yellow a/v cables for component video. especially with a long run of cable, an impedance mismatch could occur with lower quality a/v cables because sometimes the audio terminations(red/white)of the cables are not close enough to the 75 ohms. if you get enough of a mismatch then reflection of the signal can cause some distortion in the picture (i think this would cause a kind of "ghosted" image where thers a faint image next to the real one, the same thing that can happen in the cable tv signal on some channels). component video cables are usually especially careful about getting closer to the 75 ohms to make sure there is no impedance mismatch. if you see no distortion in the picture though, theres surely nothing to worry about.
