Ok Im really new to sony vegas, Infact I only started using it about 2 days ago. What Im trying to do is to turn the clip black and white, but leave in one colour. Ive worked out how using the crop and masking tools etc, but Im having trouble with this next bit. Im guessing that you need to paste another layer of the clip for the background. When I do this both clips turn to black and white, and when I click off one they both turn back to colour, how can I keep one of the clips in colour? I hope that made sense?
OK - what I failed to remember was that there IS an additional tweak you can do with 2ndCC, and that IS to add a Track 2, with a copy of the Event, make that black and white, BUT go back into 2ndCC and reduce the ALPHA channel. What all this does is to allow your T1 2ndCC parts to be transparent THUS allowing the T2 BnW Event to show clear.
And another thing . .
If you are needing to remove event MORE not wanted colour, add another 2ndCC and drag over and remove saturation FOR THAT instance of 2ndCC. Don;t forget to reduce the ALPHA to to allow your T2 BnW Track Event to show through too.