component video is RGB for video +RW for audio. you can not get away with just connecting the blue but would need the red and green as well.
your receiver according to a rear shot
http
/s564.photobucket.com/user/jj_cat24/media/IMG_1050.jpg.html looks to have composite video, svideo and component video connections. the best quality video passthrough would be component however given the age of the unit you might be better off just going hdmi from source to tv with a hdmi audio extractor in between and sending off a R+W rca connection to the receiver for audio. in that manner the receiver would be out of the video loop (it would just handle audio) so you will not lose any clarity. if your source device doesnt have hdmi output then i wouldnt worry about it and component would be fine.
keep in mind that hooking up in that manner will only generate 2.0 sound or via dolby modes it could fake surround sound. if you want 5.1 sound and have a device capable of outputting 5.1 sound then you would want to use the optical ports as in your manual
http
/download.yamaha.com/api/asset/file/?language=en&site=usa.yamaha.com&asset_id=35403
the only way to accept a 6ch input is via optical so either you would need a direct connection from source via the optical jack (and run hdmi video straight to tv) or a conversion box (similar to what i mentioned above but with 5.1 optical out and hdmi video passthrough to tv).
note: you could still use video passthrough if you wanted. depending on cable quality and other factors component video can be similar to hdmi on quality. its just when you are talking of using adapters on both ends because you use native hdmi input/output devices that it starts to get questionable in terms of quality loss.