JUst to update, got colours working in winxp, by using the drivers that came on the cd with the card. Old, old driver, but at least I got colours in tvout now!
Newer vanilla nvidia.com drivers wouldnt give me colour, no matter if I choosed composite, svideo, autodetect nor if I changed the tv settings.
Oh well, tis fine for now. And games arent complaining about the relatively old drivers, so all good for now.
(and i agree with the lack of documentation, that imo is not acceptable).