You can add color back into a brick or concrete paver by using ColorStain UV concrete stain (or dye) and then sealing over with a clear sealer.  This is a much more natural and long-lasting solution to coloring pavers than using a paint.  Another option for coloring is to add the color directly to the sealer using ColorShot so you stain and seal at the same time.  A range of colors are avialable for both options.