To encapsulate what Rob and Lawrence are saying... The native NES video output is very primitive next to the video signal options we have available to us now. There is no advantage to producing HDMI or component video from the Famicom hardware because there won't be any improvement in the quality, color or sharpness of the image. Upscaling or signal conversion options are always available, but that's a lot of expense for very little reward. The chip-swapping RGB mod is about the best you'll be able to produce, and again that's a lot of effort with not a lot of payoff.
-KKC, up too late playing Yakuza.