How do I convert an existing PPT 2007 presentation that is in color to black and white so that when it's saved, it is saved without color? I tried viewing in B/W and then saving but this doesn't seem to work.

I think to actually convert the PPT to black and white you would have to actually change the color scheme. If there are color images, you can change them to grayscale under Format Picture/Picture/Recolor.