Yellow will be good actually. It will contrast well with the black and white. Silver would be crap because you wouldnt be able to see it very well. Gold would probably work quite well though, it looks good on the new Italia shirt. The style of the letters also matters though.
If think it will look great because the badge is gold , so is the nike tick and so is the trim around the scuddetto badge. 'juventino' where did you hear this?
I don't think that the issue should be the color of the numbers, what about the pink away jerseys!!! i know that it was the original color and all, but don't u think we could do without it?