After dusting off the old N64 that I still had, and the games that were on it, I figured I could plug it into the HDTV that I had in my room, figuring that it would work. Well, it did, but there was no color; only black and white. I figured the A/V cable was the culprit, and switched it out with a spare that I had. Replugged it in, and I still got a black and white picture. Would I have to trade N64s to get the color to work? Or am I out of luck? The HDTV I have is a 32" LCD Samsung HDTV.
I also have a 32" LCD Samsung HDTV (LN32A450C1D), which I was just able to play my N64 and Ocarina of Time in full colour, so it is not likely a problem with your TV, but perhaps in how you have it connected to your N64.
My TV is a couple of years old, so if yours is newer (or older) the audio/video connections may have changed, but on mine, the standard A/V (yellow video, white and red audio) connection is on the right-hand side of the TV, which works perfectly for the N64 A/V cables.:)
Also, or if your TV no longer has the side connection, there is another A/V connection port on the back of the Samsung TV, which uses the "Component" (Reddish-Orange, Blue and Green video) ports, which you inset the yellow cable into the "Green" port of your TV and use on the same row of ports, the white and red for the audio.
So try either of those and see if you get any colour and if not, then perhaps try feeding the N64 video (and audio) through another electronic device such as a VCR or DVD player, as perhaps if your TV is extremely new, then perhaps it is having trouble processing the vidoe correctly, as unfortunately some newer TVs are being manufactured now that are no longer compatible with the older video game consoles.
If you're using component inputs (green/blue/red/yellow/red) try putting the yellow part of the N64 cable into the green input. If that doesn't work.. try red and blue. lol If that doesn't work then I don't know what to tell you.
If you're using composite inputs (red/yellow/white) on your TV then try the above.
What's the big deal? How come your complaining about black and white N64 games, but you wouldn't complain about black and white GameBoy or Game & Watch games? It's just like how people complain about bad graphics in recent games, but not for N64 games. It's just silly.
Unless your TV has either a Yellow connector or the Green component input on the TV can double as composite, you'll always get black and white.
The way component video works is green is brightness (how black or white the pixel is), while blue and red are color. One possible suggestion though: Look to see if you have an input for S-Video. You can pick up a set of cables that will work on Gamecube (which are also backwards compatible with N64 and SNES) for around $10 or so.
As for the black-and-white N64 games vs Gameboy or Game & Watch, Gameboy and Game & Watch were designed for black and white, with the graphics adjusted for it. There are N64 games that rely on color cues to play. Try playing Ocarina of Time or Majora's Mask in black and white and equip the Fire/Ice/Spirit arrows, equip the correct tunic, etc. Mario 64, the switch levels and then the boxes associated with the switch.
edit: if your VCR has a yellow input and component out, more than likely you should be able to hook your N64 into the VCR and play it that way. Just a heads-up though, there's a bit of input lag doing it that way. (maybe a quarter to half a second, that's what I've noticed on a Gamecube)
yes it sounds likes you either have the video cable plugged into the wrong input, or you have your tv on the wrong input. if you have a yellow connector that is where you want to plug it in. as mentioned some tv's allow you to plug it into one of the red/green/blue component plugs, however, when you do that, you have to make sure you switch the tv to an av input, not the component input ypbpr as that one requires the red/green/blue component cables. if unsure lookup a manual for your tv model online to see if/how its supported.