On photoshop CS when you do a "canvas size" at the bottom you get a "canvas extension colour". Select black (or whatever colour you want) then add say 2 or 5 pixels around the photo.

Then do another "canvas size" but this time select "canvas extension colour" but choose white or another colour. Add say 5 or 10 pixels around the photo.

Hope that helps. There are other ways of doing it too...