Although I haven't done this yet with my B&W pics. I was told to do them in color, especially if you have colorization in them or sepia. I did have an old document copied in color and where the paper was yellowed that shows on the color copy, so I think if your B&W have any yellowing or discoloration this would show on a color copy. I would try one pic both ways and see how they come out, the color copies are a lot more expensive, but worth it.

Dear Kelly,
I made color copies of some old black and whites of my brother as a baby and I scanned them on the computer that had a touch up feature in it and it cleaned up a lot of the yellowing, creases, etc. I was also able to crop it on the computer and enlarge the image. I was great. After I was happy with the adjustsments I had made with the computer I changed the printer paper to picture paper made for printers. WHile it does not look exactly like a photo from a film place it does look a lot better than it did to begin with. Penny

I had photos of my parents that were black and white, but tinted. They were 8x10 photos.

I took them to Kinko and had color photo copies of them done on glossy paper. They turned out great and look just like the originals.