I have a Geforce 4 Ti4200 using the latest legacy driver that I have configured to use with two monitors, one with DVI and the other with VGA. This has worked well and never given me any problems.
But now I got myself an S-Video cable as well that I wish to connect to my tv. There are some problems though.

First of all, I can't get it to output a signal on all three screens at the same time. I can only use two screens simultaneously.
Second, when I use only my TFT monitor (DVI) and the TV, the TV gets a picture, but in black and white like it's set on NTSC when it should be PAL-B. But I can't find an option to set the TV format in nvidia-settings. I tried setting it in xorg.conf manually, but it didn't work anyway.

Then I read that you should play around with the saturation option in nvidia-settings until you get color. The only problem is that I can't find such an option there. There's Brightness, Contrast and Gamma, but no Saturation.

So my questions are:
Can I get the GPU to output on all three displays at the same time? Preferably with Xinerama.
And where the hell is the Saturation option in nvidia-settings that everyone is writing about?!

gamma = saturation?
If old memory is true, your video chips can't do both. Not enough video processing ability to feed all your outputs. Have you found any documentation of ability to do all 3 outputs in Linux? Have you tried S-video alone to get color correct?